diff --git a/packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md b/packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md
index 1027affdf24a..fa0ac1051482 100644
--- a/packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md
+++ b/packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.6.0
+
+* Move MethodChannel code to MethodChannelGoogleMapsFlutter (Flutter Platform Interface)
+
 ## 0.5.25+3
 
 * Rename 'Page' in the example app to avoid type conflict with the Flutter Framework.
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/google_maps_flutter.dart b/packages/google_maps_flutter/google_maps_flutter/lib/google_maps_flutter.dart
index 5f3889f7b2f1..a17b30ca6226 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/google_maps_flutter.dart
+++ b/packages/google_maps_flutter/google_maps_flutter/lib/google_maps_flutter.dart
@@ -13,22 +13,36 @@ import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
-part 'src/bitmap.dart';
-part 'src/callbacks.dart';
-part 'src/camera.dart';
-part 'src/cap.dart';
-part 'src/circle.dart';
-part 'src/circle_updates.dart';
+import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';
+import 'package:google_maps_flutter_platform_interface/src/method_channel/method_channel_google_maps_flutter.dart';
+
+export 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart'
+    show
+        ArgumentCallbacks,
+        ArgumentCallback,
+        BitmapDescriptor,
+        CameraPosition,
+        CameraPositionCallback,
+        CameraTargetBounds,
+        CameraUpdate,
+        Cap,
+        Circle,
+        CircleId,
+        InfoWindow,
+        JointType,
+        LatLng,
+        LatLngBounds,
+        MapStyleException,
+        MapType,
+        Marker,
+        MarkerId,
+        MinMaxZoomPreference,
+        PatternItem,
+        Polygon,
+        PolygonId,
+        Polyline,
+        PolylineId,
+        ScreenCoordinate;
+
 part 'src/controller.dart';
 part 'src/google_map.dart';
-part 'src/joint_type.dart';
-part 'src/location.dart';
-part 'src/marker.dart';
-part 'src/marker_updates.dart';
-part 'src/pattern_item.dart';
-part 'src/polygon.dart';
-part 'src/polygon_updates.dart';
-part 'src/polyline.dart';
-part 'src/polyline_updates.dart';
-part 'src/screen_coordinate.dart';
-part 'src/ui.dart';
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/controller.dart b/packages/google_maps_flutter/google_maps_flutter/lib/src/controller.dart
index 750bb69393e7..c87b2dacb09c 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/controller.dart
+++ b/packages/google_maps_flutter/google_maps_flutter/lib/src/controller.dart
@@ -4,14 +4,20 @@
 
 part of google_maps_flutter;
 
+final GoogleMapsFlutterPlatform _googleMapsFlutterPlatform =
+    GoogleMapsFlutterPlatform.instance;
+
 /// Controller for a single GoogleMap instance running on the host platform.
 class GoogleMapController {
+  /// The mapId for this controller
+  final int mapId;
+
   GoogleMapController._(
-    this.channel,
     CameraPosition initialCameraPosition,
-    this._googleMapState,
-  ) : assert(channel != null) {
-    channel.setMethodCallHandler(_handleMethodCall);
+    this._googleMapState, {
+    @required this.mapId,
+  }) : assert(_googleMapsFlutterPlatform != null) {
+    _connectStreams(mapId);
   }
 
   /// Initialize control of a [GoogleMap] with [id].
@@ -24,72 +30,66 @@ class GoogleMapController {
     _GoogleMapState googleMapState,
   ) async {
     assert(id != null);
-    final MethodChannel channel =
-        MethodChannel('plugins.flutter.io/google_maps_$id');
-    await channel.invokeMethod<void>('map#waitForMap');
+    await _googleMapsFlutterPlatform.init(id);
     return GoogleMapController._(
-      channel,
       initialCameraPosition,
       googleMapState,
+      mapId: id,
     );
   }
 
   /// Used to communicate with the native platform.
   ///
   /// Accessible only for testing.
+  // TODO: Remove this once tests are migrated to not need this.
   @visibleForTesting
-  final MethodChannel channel;
+  MethodChannel get channel {
+    if (_googleMapsFlutterPlatform is MethodChannelGoogleMapsFlutter) {
+      return (_googleMapsFlutterPlatform as MethodChannelGoogleMapsFlutter)
+          .channel(mapId);
+    }
+    return null;
+  }
 
   final _GoogleMapState _googleMapState;
 
-  Future<dynamic> _handleMethodCall(MethodCall call) async {
-    switch (call.method) {
-      case 'camera#onMoveStarted':
-        if (_googleMapState.widget.onCameraMoveStarted != null) {
-          _googleMapState.widget.onCameraMoveStarted();
-        }
-        break;
-      case 'camera#onMove':
-        if (_googleMapState.widget.onCameraMove != null) {
-          _googleMapState.widget.onCameraMove(
-            CameraPosition.fromMap(call.arguments['position']),
-          );
-        }
-        break;
-      case 'camera#onIdle':
-        if (_googleMapState.widget.onCameraIdle != null) {
-          _googleMapState.widget.onCameraIdle();
-        }
-        break;
-      case 'marker#onTap':
-        _googleMapState.onMarkerTap(call.arguments['markerId']);
-        break;
-      case 'marker#onDragEnd':
-        _googleMapState.onMarkerDragEnd(call.arguments['markerId'],
-            LatLng._fromJson(call.arguments['position']));
-        break;
-      case 'infoWindow#onTap':
-        _googleMapState.onInfoWindowTap(call.arguments['markerId']);
-        break;
-      case 'polyline#onTap':
-        _googleMapState.onPolylineTap(call.arguments['polylineId']);
-        break;
-      case 'polygon#onTap':
-        _googleMapState.onPolygonTap(call.arguments['polygonId']);
-        break;
-      case 'circle#onTap':
-        _googleMapState.onCircleTap(call.arguments['circleId']);
-        break;
-      case 'map#onTap':
-        _googleMapState.onTap(LatLng._fromJson(call.arguments['position']));
-        break;
-      case 'map#onLongPress':
-        _googleMapState
-            .onLongPress(LatLng._fromJson(call.arguments['position']));
-        break;
-      default:
-        throw MissingPluginException();
+  void _connectStreams(int mapId) {
+    if (_googleMapState.widget.onCameraMoveStarted != null) {
+      _googleMapsFlutterPlatform
+          .onCameraMoveStarted(mapId: mapId)
+          .listen((_) => _googleMapState.widget.onCameraMoveStarted());
     }
+    if (_googleMapState.widget.onCameraMove != null) {
+      _googleMapsFlutterPlatform.onCameraMove(mapId: mapId).listen(
+          (CameraMoveEvent e) => _googleMapState.widget.onCameraMove(e.value));
+    }
+    if (_googleMapState.widget.onCameraIdle != null) {
+      _googleMapsFlutterPlatform
+          .onCameraIdle(mapId: mapId)
+          .listen((_) => _googleMapState.widget.onCameraIdle());
+    }
+    _googleMapsFlutterPlatform
+        .onMarkerTap(mapId: mapId)
+        .listen((MarkerTapEvent e) => _googleMapState.onMarkerTap(e.value));
+    _googleMapsFlutterPlatform.onMarkerDragEnd(mapId: mapId).listen(
+        (MarkerDragEndEvent e) =>
+            _googleMapState.onMarkerDragEnd(e.value, e.position));
+    _googleMapsFlutterPlatform.onInfoWindowTap(mapId: mapId).listen(
+        (InfoWindowTapEvent e) => _googleMapState.onInfoWindowTap(e.value));
+    _googleMapsFlutterPlatform
+        .onPolylineTap(mapId: mapId)
+        .listen((PolylineTapEvent e) => _googleMapState.onPolylineTap(e.value));
+    _googleMapsFlutterPlatform
+        .onPolygonTap(mapId: mapId)
+        .listen((PolygonTapEvent e) => _googleMapState.onPolygonTap(e.value));
+    _googleMapsFlutterPlatform
+        .onCircleTap(mapId: mapId)
+        .listen((CircleTapEvent e) => _googleMapState.onCircleTap(e.value));
+    _googleMapsFlutterPlatform
+        .onTap(mapId: mapId)
+        .listen((MapTapEvent e) => _googleMapState.onTap(e.position));
+    _googleMapsFlutterPlatform.onLongPress(mapId: mapId).listen(
+        (MapLongPressEvent e) => _googleMapState.onLongPress(e.position));
   }
 
   /// Updates configuration options of the map user interface.
@@ -98,14 +98,10 @@ class GoogleMapController {
   /// platform side.
   ///
   /// The returned [Future] completes after listeners have been notified.
-  Future<void> _updateMapOptions(Map<String, dynamic> optionsUpdate) async {
+  Future<void> _updateMapOptions(Map<String, dynamic> optionsUpdate) {
     assert(optionsUpdate != null);
-    await channel.invokeMethod<void>(
-      'map#update',
-      <String, dynamic>{
-        'options': optionsUpdate,
-      },
-    );
+    return _googleMapsFlutterPlatform.updateMapOptions(optionsUpdate,
+        mapId: mapId);
   }
 
   /// Updates marker configuration.
@@ -114,12 +110,10 @@ class GoogleMapController {
   /// platform side.
   ///
   /// The returned [Future] completes after listeners have been notified.
-  Future<void> _updateMarkers(_MarkerUpdates markerUpdates) async {
+  Future<void> _updateMarkers(MarkerUpdates markerUpdates) {
     assert(markerUpdates != null);
-    await channel.invokeMethod<void>(
-      'markers#update',
-      markerUpdates._toMap(),
-    );
+    return _googleMapsFlutterPlatform.updateMarkers(markerUpdates,
+        mapId: mapId);
   }
 
   /// Updates polygon configuration.
@@ -128,12 +122,10 @@ class GoogleMapController {
   /// platform side.
   ///
   /// The returned [Future] completes after listeners have been notified.
-  Future<void> _updatePolygons(_PolygonUpdates polygonUpdates) async {
+  Future<void> _updatePolygons(PolygonUpdates polygonUpdates) {
     assert(polygonUpdates != null);
-    await channel.invokeMethod<void>(
-      'polygons#update',
-      polygonUpdates._toMap(),
-    );
+    return _googleMapsFlutterPlatform.updatePolygons(polygonUpdates,
+        mapId: mapId);
   }
 
   /// Updates polyline configuration.
@@ -142,12 +134,10 @@ class GoogleMapController {
   /// platform side.
   ///
   /// The returned [Future] completes after listeners have been notified.
-  Future<void> _updatePolylines(_PolylineUpdates polylineUpdates) async {
+  Future<void> _updatePolylines(PolylineUpdates polylineUpdates) {
     assert(polylineUpdates != null);
-    await channel.invokeMethod<void>(
-      'polylines#update',
-      polylineUpdates._toMap(),
-    );
+    return _googleMapsFlutterPlatform.updatePolylines(polylineUpdates,
+        mapId: mapId);
   }
 
   /// Updates circle configuration.
@@ -156,32 +146,26 @@ class GoogleMapController {
   /// platform side.
   ///
   /// The returned [Future] completes after listeners have been notified.
-  Future<void> _updateCircles(_CircleUpdates circleUpdates) async {
+  Future<void> _updateCircles(CircleUpdates circleUpdates) {
     assert(circleUpdates != null);
-    await channel.invokeMethod<void>(
-      'circles#update',
-      circleUpdates._toMap(),
-    );
+    return _googleMapsFlutterPlatform.updateCircles(circleUpdates,
+        mapId: mapId);
   }
 
   /// Starts an animated change of the map camera position.
   ///
   /// The returned [Future] completes after the change has been started on the
   /// platform side.
-  Future<void> animateCamera(CameraUpdate cameraUpdate) async {
-    await channel.invokeMethod<void>('camera#animate', <String, dynamic>{
-      'cameraUpdate': cameraUpdate._toJson(),
-    });
+  Future<void> animateCamera(CameraUpdate cameraUpdate) {
+    return _googleMapsFlutterPlatform.animateCamera(cameraUpdate, mapId: mapId);
   }
 
   /// Changes the map camera position.
   ///
   /// The returned [Future] completes after the change has been made on the
   /// platform side.
-  Future<void> moveCamera(CameraUpdate cameraUpdate) async {
-    await channel.invokeMethod<void>('camera#move', <String, dynamic>{
-      'cameraUpdate': cameraUpdate._toJson(),
-    });
+  Future<void> moveCamera(CameraUpdate cameraUpdate) {
+    return _googleMapsFlutterPlatform.moveCamera(cameraUpdate, mapId: mapId);
   }
 
   /// Sets the styling of the base map.
@@ -197,23 +181,13 @@ class GoogleMapController {
   /// Also, refer [iOS](https://developers.google.com/maps/documentation/ios-sdk/style-reference)
   /// and [Android](https://developers.google.com/maps/documentation/android-sdk/style-reference)
   /// style reference for more information regarding the supported styles.
-  Future<void> setMapStyle(String mapStyle) async {
-    final List<dynamic> successAndError =
-        await channel.invokeMethod<List<dynamic>>('map#setStyle', mapStyle);
-    final bool success = successAndError[0];
-    if (!success) {
-      throw MapStyleException(successAndError[1]);
-    }
+  Future<void> setMapStyle(String mapStyle) {
+    return _googleMapsFlutterPlatform.setMapStyle(mapStyle, mapId: mapId);
   }
 
   /// Return [LatLngBounds] defining the region that is visible in a map.
-  Future<LatLngBounds> getVisibleRegion() async {
-    final Map<String, dynamic> latLngBounds =
-        await channel.invokeMapMethod<String, dynamic>('map#getVisibleRegion');
-    final LatLng southwest = LatLng._fromJson(latLngBounds['southwest']);
-    final LatLng northeast = LatLng._fromJson(latLngBounds['northeast']);
-
-    return LatLngBounds(northeast: northeast, southwest: southwest);
+  Future<LatLngBounds> getVisibleRegion() {
+    return _googleMapsFlutterPlatform.getVisibleRegion(mapId: mapId);
   }
 
   /// Return [ScreenCoordinate] of the [LatLng] in the current map view.
@@ -221,20 +195,16 @@ class GoogleMapController {
   /// A projection is used to translate between on screen location and geographic coordinates.
   /// Screen location is in screen pixels (not display pixels) with respect to the top left corner
   /// of the map, not necessarily of the whole screen.
-  Future<ScreenCoordinate> getScreenCoordinate(LatLng latLng) async {
-    final Map<String, int> point = await channel.invokeMapMethod<String, int>(
-        'map#getScreenCoordinate', latLng._toJson());
-    return ScreenCoordinate(x: point['x'], y: point['y']);
+  Future<ScreenCoordinate> getScreenCoordinate(LatLng latLng) {
+    return _googleMapsFlutterPlatform.getScreenCoordinate(latLng, mapId: mapId);
   }
 
   /// Returns [LatLng] corresponding to the [ScreenCoordinate] in the current map view.
   ///
   /// Returned [LatLng] corresponds to a screen location. The screen location is specified in screen
   /// pixels (not display pixels) relative to the top left of the map, not top left of the whole screen.
-  Future<LatLng> getLatLng(ScreenCoordinate screenCoordinate) async {
-    final List<dynamic> latLng = await channel.invokeMethod<List<dynamic>>(
-        'map#getLatLng', screenCoordinate._toJson());
-    return LatLng(latLng[0], latLng[1]);
+  Future<LatLng> getLatLng(ScreenCoordinate screenCoordinate) {
+    return _googleMapsFlutterPlatform.getLatLng(screenCoordinate, mapId: mapId);
   }
 
   /// Programmatically show the Info Window for a [Marker].
@@ -245,10 +215,10 @@ class GoogleMapController {
   /// * See also:
   ///   * [hideMarkerInfoWindow] to hide the Info Window.
   ///   * [isMarkerInfoWindowShown] to check if the Info Window is showing.
-  Future<void> showMarkerInfoWindow(MarkerId markerId) async {
+  Future<void> showMarkerInfoWindow(MarkerId markerId) {
     assert(markerId != null);
-    await channel.invokeMethod<void>(
-        'markers#showInfoWindow', <String, String>{'markerId': markerId.value});
+    return _googleMapsFlutterPlatform.showMarkerInfoWindow(markerId,
+        mapId: mapId);
   }
 
   /// Programmatically hide the Info Window for a [Marker].
@@ -259,10 +229,10 @@ class GoogleMapController {
   /// * See also:
   ///   * [showMarkerInfoWindow] to show the Info Window.
   ///   * [isMarkerInfoWindowShown] to check if the Info Window is showing.
-  Future<void> hideMarkerInfoWindow(MarkerId markerId) async {
+  Future<void> hideMarkerInfoWindow(MarkerId markerId) {
     assert(markerId != null);
-    await channel.invokeMethod<void>(
-        'markers#hideInfoWindow', <String, String>{'markerId': markerId.value});
+    return _googleMapsFlutterPlatform.hideMarkerInfoWindow(markerId,
+        mapId: mapId);
   }
 
   /// Returns `true` when the [InfoWindow] is showing, `false` otherwise.
@@ -273,21 +243,19 @@ class GoogleMapController {
   /// * See also:
   ///   * [showMarkerInfoWindow] to show the Info Window.
   ///   * [hideMarkerInfoWindow] to hide the Info Window.
-  Future<bool> isMarkerInfoWindowShown(MarkerId markerId) async {
+  Future<bool> isMarkerInfoWindowShown(MarkerId markerId) {
     assert(markerId != null);
-    return await channel.invokeMethod<bool>('markers#isInfoWindowShown',
-        <String, String>{'markerId': markerId.value});
+    return _googleMapsFlutterPlatform.isMarkerInfoWindowShown(markerId,
+        mapId: mapId);
   }
 
   /// Returns the current zoom level of the map
-  Future<double> getZoomLevel() async {
-    final double zoomLevel =
-        await channel.invokeMethod<double>('map#getZoomLevel');
-    return zoomLevel;
+  Future<double> getZoomLevel() {
+    return _googleMapsFlutterPlatform.getZoomLevel(mapId: mapId);
   }
 
   /// Returns the image bytes of the map
-  Future<Uint8List> takeSnapshot() async {
-    return await channel.invokeMethod<Uint8List>('map#takeSnapshot');
+  Future<Uint8List> takeSnapshot() {
+    return _googleMapsFlutterPlatform.takeSnapshot(mapId: mapId);
   }
 }
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/google_map.dart b/packages/google_maps_flutter/google_maps_flutter/lib/src/google_map.dart
index f6a413a82ffb..be15e2238b89 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/google_map.dart
+++ b/packages/google_maps_flutter/google_maps_flutter/lib/src/google_map.dart
@@ -10,14 +10,6 @@ part of google_maps_flutter;
 /// map is created.
 typedef void MapCreatedCallback(GoogleMapController controller);
 
-/// Callback that receives updates to the camera position.
-///
-/// This callback is triggered when the platform Google Map
-/// registers a camera movement.
-///
-/// This is used in [GoogleMap.onCameraMove].
-typedef void CameraPositionCallback(CameraPosition position);
-
 /// A widget which displays a map with data obtained from the Google Maps service.
 class GoogleMap extends StatefulWidget {
   /// Creates a widget displaying data from Google Maps services.
@@ -214,41 +206,26 @@ class _GoogleMapState extends State<GoogleMap> {
     final Map<String, dynamic> creationParams = <String, dynamic>{
       'initialCameraPosition': widget.initialCameraPosition?.toMap(),
       'options': _googleMapOptions.toMap(),
-      'markersToAdd': _serializeMarkerSet(widget.markers),
-      'polygonsToAdd': _serializePolygonSet(widget.polygons),
-      'polylinesToAdd': _serializePolylineSet(widget.polylines),
-      'circlesToAdd': _serializeCircleSet(widget.circles),
+      'markersToAdd': serializeMarkerSet(widget.markers),
+      'polygonsToAdd': serializePolygonSet(widget.polygons),
+      'polylinesToAdd': serializePolylineSet(widget.polylines),
+      'circlesToAdd': serializeCircleSet(widget.circles),
     };
-    if (defaultTargetPlatform == TargetPlatform.android) {
-      return AndroidView(
-        viewType: 'plugins.flutter.io/google_maps',
-        onPlatformViewCreated: onPlatformViewCreated,
-        gestureRecognizers: widget.gestureRecognizers,
-        creationParams: creationParams,
-        creationParamsCodec: const StandardMessageCodec(),
-      );
-    } else if (defaultTargetPlatform == TargetPlatform.iOS) {
-      return UiKitView(
-        viewType: 'plugins.flutter.io/google_maps',
-        onPlatformViewCreated: onPlatformViewCreated,
-        gestureRecognizers: widget.gestureRecognizers,
-        creationParams: creationParams,
-        creationParamsCodec: const StandardMessageCodec(),
-      );
-    }
-
-    return Text(
-        '$defaultTargetPlatform is not yet supported by the maps plugin');
+    return _googleMapsFlutterPlatform.buildView(
+      creationParams,
+      widget.gestureRecognizers,
+      onPlatformViewCreated,
+    );
   }
 
   @override
   void initState() {
     super.initState();
     _googleMapOptions = _GoogleMapOptions.fromWidget(widget);
-    _markers = _keyByMarkerId(widget.markers);
-    _polygons = _keyByPolygonId(widget.polygons);
-    _polylines = _keyByPolylineId(widget.polylines);
-    _circles = _keyByCircleId(widget.circles);
+    _markers = keyByMarkerId(widget.markers);
+    _polygons = keyByPolygonId(widget.polygons);
+    _polylines = keyByPolylineId(widget.polylines);
+    _circles = keyByCircleId(widget.circles);
   }
 
   @override
@@ -278,32 +255,32 @@ class _GoogleMapState extends State<GoogleMap> {
     final GoogleMapController controller = await _controller.future;
     // ignore: unawaited_futures
     controller._updateMarkers(
-        _MarkerUpdates.from(_markers.values.toSet(), widget.markers));
-    _markers = _keyByMarkerId(widget.markers);
+        MarkerUpdates.from(_markers.values.toSet(), widget.markers));
+    _markers = keyByMarkerId(widget.markers);
   }
 
   void _updatePolygons() async {
     final GoogleMapController controller = await _controller.future;
     // ignore: unawaited_futures
     controller._updatePolygons(
-        _PolygonUpdates.from(_polygons.values.toSet(), widget.polygons));
-    _polygons = _keyByPolygonId(widget.polygons);
+        PolygonUpdates.from(_polygons.values.toSet(), widget.polygons));
+    _polygons = keyByPolygonId(widget.polygons);
   }
 
   void _updatePolylines() async {
     final GoogleMapController controller = await _controller.future;
     // ignore: unawaited_futures
     controller._updatePolylines(
-        _PolylineUpdates.from(_polylines.values.toSet(), widget.polylines));
-    _polylines = _keyByPolylineId(widget.polylines);
+        PolylineUpdates.from(_polylines.values.toSet(), widget.polylines));
+    _polylines = keyByPolylineId(widget.polylines);
   }
 
   void _updateCircles() async {
     final GoogleMapController controller = await _controller.future;
     // ignore: unawaited_futures
     controller._updateCircles(
-        _CircleUpdates.from(_circles.values.toSet(), widget.circles));
-    _circles = _keyByCircleId(widget.circles);
+        CircleUpdates.from(_circles.values.toSet(), widget.circles));
+    _circles = keyByCircleId(widget.circles);
   }
 
   Future<void> onPlatformViewCreated(int id) async {
@@ -318,45 +295,39 @@ class _GoogleMapState extends State<GoogleMap> {
     }
   }
 
-  void onMarkerTap(String markerIdParam) {
-    assert(markerIdParam != null);
-    final MarkerId markerId = MarkerId(markerIdParam);
+  void onMarkerTap(MarkerId markerId) {
+    assert(markerId != null);
     if (_markers[markerId]?.onTap != null) {
       _markers[markerId].onTap();
     }
   }
 
-  void onMarkerDragEnd(String markerIdParam, LatLng position) {
-    assert(markerIdParam != null);
-    final MarkerId markerId = MarkerId(markerIdParam);
+  void onMarkerDragEnd(MarkerId markerId, LatLng position) {
+    assert(markerId != null);
     if (_markers[markerId]?.onDragEnd != null) {
       _markers[markerId].onDragEnd(position);
     }
   }
 
-  void onPolygonTap(String polygonIdParam) {
-    assert(polygonIdParam != null);
-    final PolygonId polygonId = PolygonId(polygonIdParam);
+  void onPolygonTap(PolygonId polygonId) {
+    assert(polygonId != null);
     _polygons[polygonId].onTap();
   }
 
-  void onPolylineTap(String polylineIdParam) {
-    assert(polylineIdParam != null);
-    final PolylineId polylineId = PolylineId(polylineIdParam);
+  void onPolylineTap(PolylineId polylineId) {
+    assert(polylineId != null);
     if (_polylines[polylineId]?.onTap != null) {
       _polylines[polylineId].onTap();
     }
   }
 
-  void onCircleTap(String circleIdParam) {
-    assert(circleIdParam != null);
-    final CircleId circleId = CircleId(circleIdParam);
+  void onCircleTap(CircleId circleId) {
+    assert(circleId != null);
     _circles[circleId].onTap();
   }
 
-  void onInfoWindowTap(String markerIdParam) {
-    assert(markerIdParam != null);
-    final MarkerId markerId = MarkerId(markerIdParam);
+  void onInfoWindowTap(MarkerId markerId) {
+    assert(markerId != null);
     if (_markers[markerId]?.infoWindow?.onTap != null) {
       _markers[markerId].infoWindow.onTap();
     }
@@ -465,9 +436,9 @@ class _GoogleMapOptions {
 
     addIfNonNull('compassEnabled', compassEnabled);
     addIfNonNull('mapToolbarEnabled', mapToolbarEnabled);
-    addIfNonNull('cameraTargetBounds', cameraTargetBounds?._toJson());
+    addIfNonNull('cameraTargetBounds', cameraTargetBounds?.toJson());
     addIfNonNull('mapType', mapType?.index);
-    addIfNonNull('minMaxZoomPreference', minMaxZoomPreference?._toJson());
+    addIfNonNull('minMaxZoomPreference', minMaxZoomPreference?.toJson());
     addIfNonNull('rotateGesturesEnabled', rotateGesturesEnabled);
     addIfNonNull('scrollGesturesEnabled', scrollGesturesEnabled);
     addIfNonNull('tiltGesturesEnabled', tiltGesturesEnabled);
diff --git a/packages/google_maps_flutter/google_maps_flutter/pubspec.yaml b/packages/google_maps_flutter/google_maps_flutter/pubspec.yaml
index 0f88a9a0ad18..58f0439cd01f 100644
--- a/packages/google_maps_flutter/google_maps_flutter/pubspec.yaml
+++ b/packages/google_maps_flutter/google_maps_flutter/pubspec.yaml
@@ -1,12 +1,14 @@
 name: google_maps_flutter
 description: A Flutter plugin for integrating Google Maps in iOS and Android applications.
 homepage: https://github.com/flutter/plugins/tree/master/packages/google_maps_flutter/google_maps_flutter
-version: 0.5.25+3
+version: 0.6.0
 
 dependencies:
   flutter:
     sdk: flutter
   flutter_plugin_android_lifecycle: ^1.0.0
+  google_maps_flutter_platform_interface:
+    path: ../google_maps_flutter_platform_interface
 
 dev_dependencies:
   flutter_test:
@@ -27,6 +29,8 @@ flutter:
         pluginClass: GoogleMapsPlugin
       ios:
         pluginClass: FLTGoogleMapsPlugin
+      web:
+        default_package: google_maps_flutter_web
 
 environment:
   sdk: ">=2.0.0-dev.47.0 <3.0.0"
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/CHANGELOG.md b/packages/google_maps_flutter/google_maps_flutter_platform_interface/CHANGELOG.md
new file mode 100644
index 000000000000..0d8803f93540
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/CHANGELOG.md
@@ -0,0 +1,3 @@
+## 1.0.0
+
+* Initial release.
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/LICENSE b/packages/google_maps_flutter/google_maps_flutter_platform_interface/LICENSE
new file mode 100644
index 000000000000..8940a4be1b58
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/LICENSE
@@ -0,0 +1,27 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/README.md b/packages/google_maps_flutter/google_maps_flutter_platform_interface/README.md
new file mode 100644
index 000000000000..6489ba39cbd8
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/README.md
@@ -0,0 +1,26 @@
+# google_maps_flutter_platform_interface
+
+A common platform interface for the [`google_maps_flutter`][1] plugin.
+
+This interface allows platform-specific implementations of the `google_maps_flutter`
+plugin, as well as the plugin itself, to ensure they are supporting the
+same interface.
+
+# Usage
+
+To implement a new platform-specific implementation of `google_maps_flutter`, extend
+[`GoogleMapsFlutterPlatform`][2] with an implementation that performs the
+platform-specific behavior, and when you register your plugin, set the default
+`GoogleMapsFlutterPlatform` by calling
+`GoogleMapsFlutterPlatform.instance = MyPlatformGoogleMapsFlutter()`.
+
+# Note on breaking changes
+
+Strongly prefer non-breaking changes (such as adding a method to the interface)
+over breaking changes for this package.
+
+See https://flutter.dev/go/platform-interface-breaking-changes for a discussion
+on why a less-clean interface is preferable to a breaking change.
+
+[1]: ../google_maps_flutter
+[2]: lib/google_maps_flutter_platform_interface.dart
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/google_maps_flutter_platform_interface.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/google_maps_flutter_platform_interface.dart
new file mode 100644
index 000000000000..cb28b40470fd
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/google_maps_flutter_platform_interface.dart
@@ -0,0 +1,7 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+export 'src/platform_interface/google_maps_flutter_platform.dart';
+export 'src/types/types.dart';
+export 'src/events/map_event.dart';
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/events/map_event.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/events/map_event.dart
new file mode 100644
index 000000000000..c462b4b182e2
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/events/map_event.dart
@@ -0,0 +1,153 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';
+import 'package:google_maps_flutter_platform_interface/src/method_channel/method_channel_google_maps_flutter.dart';
+
+/// Generic Event coming from the native side of Maps.
+///
+/// All MapEvents contain the `mapId` that originated the event. This should
+/// never be `null`.
+///
+/// The `<T>` on this event represents the type of the `value` that is
+/// contained within the event.
+///
+/// This class is used as a base class for all the events that might be
+/// triggered from a Map, but it is never used directly as an event type.
+///
+/// Do NOT instantiate new events like `MapEvent<ValueType>(mapId, val)` directly,
+/// use a specific class instead:
+///
+/// Do `class NewEvent extend MapEvent<ValueType>` when creating your own events.
+/// See below for examples: `CameraMoveStartedEvent`, `MarkerDragEndEvent`...
+/// These events are more semantic and pleasant to use than raw generics. They
+/// can be (and in fact, are) filtered by the `instanceof`-operator.
+///
+/// (See [MethodChannelGoogleMapsFlutter.onCameraMoveStarted], for example)
+///
+/// If your event needs a `position`, alongside the `value`, do
+/// `extends _PositionedMapEvent<ValueType>` instead. This adds a `LatLng position`
+/// attribute.
+///
+/// If your event *only* needs a `position`, do `extend _PositionedMapEvent<void>`
+/// do NOT `extend MapEvent<LatLng>`. The former lets consumers of these
+/// events to access the `.position` property, rather than the more generic `.value`
+/// yielded from the latter.
+class MapEvent<T> {
+  /// The ID of the Map this event is associated to.
+  final int mapId;
+
+  /// The value wrapped by this event
+  final T value;
+
+  /// Build a Map Event, that relates a mapId with a given value.
+  ///
+  /// The `mapId` is the id of the map that triggered the event.
+  /// `value` may be `null` in events that don't transport any meaningful data.
+  MapEvent(this.mapId, this.value);
+}
+
+/// A `MapEvent` associated to a `position`.
+class _PositionedMapEvent<T> extends MapEvent<T> {
+  /// The position where this event happened.
+  final LatLng position;
+
+  /// Build a Positioned MapEvent, that relates a mapId and a position with a value.
+  ///
+  /// The `mapId` is the id of the map that triggered the event.
+  /// `value` may be `null` in events that don't transport any meaningful data.
+  _PositionedMapEvent(int mapId, this.position, T value) : super(mapId, value);
+}
+
+// The following events are the ones exposed to the end user. They are semantic extensions
+// of the two base classes above.
+//
+// These events are used to create the appropriate [Stream] objects, with information
+// coming from the native side.
+
+/// An event fired when the Camera of a [mapId] starts moving.
+class CameraMoveStartedEvent extends MapEvent<void> {
+  /// Build a CameraMoveStarted Event triggered from the map represented by `mapId`.
+  CameraMoveStartedEvent(int mapId) : super(mapId, null);
+}
+
+/// An event fired while the Camera of a [mapId] moves.
+class CameraMoveEvent extends MapEvent<CameraPosition> {
+  /// Build a CameraMove Event triggered from the map represented by `mapId`.
+  ///
+  /// The `value` of this event is a [CameraPosition] object with the current position of the Camera.
+  CameraMoveEvent(int mapId, CameraPosition position) : super(mapId, position);
+}
+
+/// An event fired when the Camera of a [mapId] becomes idle.
+class CameraIdleEvent extends MapEvent<void> {
+  /// Build a CameraIdle Event triggered from the map represented by `mapId`.
+  CameraIdleEvent(int mapId) : super(mapId, null);
+}
+
+/// An event fired when a [Marker] is tapped.
+class MarkerTapEvent extends MapEvent<MarkerId> {
+  /// Build a MarkerTap Event triggered from the map represented by `mapId`.
+  ///
+  /// The `value` of this event is a [MarkerId] object that represents the tapped Marker.
+  MarkerTapEvent(int mapId, MarkerId markerId) : super(mapId, markerId);
+}
+
+/// An event fired when an [InfoWindow] is tapped.
+class InfoWindowTapEvent extends MapEvent<MarkerId> {
+  /// Build an InfoWindowTap Event triggered from the map represented by `mapId`.
+  ///
+  /// The `value` of this event is a [MarkerId] object that represents the tapped InfoWindow.
+  InfoWindowTapEvent(int mapId, MarkerId markerId) : super(mapId, markerId);
+}
+
+/// An event fired when a [Marker] is dragged to a new [LatLng].
+class MarkerDragEndEvent extends _PositionedMapEvent<MarkerId> {
+  /// Build a MarkerDragEnd Event triggered from the map represented by `mapId`.
+  ///
+  /// The `position` on this event is the [LatLng] on which the Marker was dropped.
+  /// The `value` of this event is a [MarkerId] object that represents the moved Marker.
+  MarkerDragEndEvent(int mapId, LatLng position, MarkerId markerId)
+      : super(mapId, position, markerId);
+}
+
+/// An event fired when a [Polyline] is tapped.
+class PolylineTapEvent extends MapEvent<PolylineId> {
+  /// Build an PolylineTap Event triggered from the map represented by `mapId`.
+  ///
+  /// The `value` of this event is a [PolylineId] object that represents the tapped Polyline.
+  PolylineTapEvent(int mapId, PolylineId polylineId) : super(mapId, polylineId);
+}
+
+/// An event fired when a [Polygon] is tapped.
+class PolygonTapEvent extends MapEvent<PolygonId> {
+  /// Build an PolygonTap Event triggered from the map represented by `mapId`.
+  ///
+  /// The `value` of this event is a [PolygonId] object that represents the tapped Polygon.
+  PolygonTapEvent(int mapId, PolygonId polygonId) : super(mapId, polygonId);
+}
+
+/// An event fired when a [Circle] is tapped.
+class CircleTapEvent extends MapEvent<CircleId> {
+  /// Build an CircleTap Event triggered from the map represented by `mapId`.
+  ///
+  /// The `value` of this event is a [CircleId] object that represents the tapped Circle.
+  CircleTapEvent(int mapId, CircleId circleId) : super(mapId, circleId);
+}
+
+/// An event fired when a Map is tapped.
+class MapTapEvent extends _PositionedMapEvent<void> {
+  /// Build an MapTap Event triggered from the map represented by `mapId`.
+  ///
+  /// The `position` of this event is the LatLng where the Map was tapped.
+  MapTapEvent(int mapId, LatLng position) : super(mapId, position, null);
+}
+
+/// An event fired when a Map is long pressed.
+class MapLongPressEvent extends _PositionedMapEvent<void> {
+  /// Build an MapTap Event triggered from the map represented by `mapId`.
+  ///
+  /// The `position` of this event is the LatLng where the Map was long pressed.
+  MapLongPressEvent(int mapId, LatLng position) : super(mapId, position, null);
+}
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/method_channel/method_channel_google_maps_flutter.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/method_channel/method_channel_google_maps_flutter.dart
new file mode 100644
index 000000000000..edbc51ab5afd
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/method_channel/method_channel_google_maps_flutter.dart
@@ -0,0 +1,477 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+import 'dart:typed_data';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter/gestures.dart';
+
+import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';
+import 'package:stream_transform/stream_transform.dart';
+
+/// An implementation of [GoogleMapsFlutterPlatform] that uses [MethodChannel] to communicate with the native code.
+///
+/// The `google_maps_flutter` plugin code itself never talks to the native code directly. It delegates
+/// all those calls to an instance of a class that extends the GoogleMapsFlutterPlatform.
+///
+/// The architecture above allows for platforms that communicate differently with the native side
+/// (like web) to have a common interface to extend.
+///
+/// This is the instance that runs when the native side talks to your Flutter app through MethodChannels,
+/// like the Android and iOS platforms.
+class MethodChannelGoogleMapsFlutter extends GoogleMapsFlutterPlatform {
+  // Keep a collection of id -> channel
+  // Every method call passes the int mapId
+  final Map<int, MethodChannel> _channels = {};
+
+  /// Accesses the MethodChannel associated to the passed mapId.
+  MethodChannel channel(int mapId) {
+    return _channels[mapId];
+  }
+
+  /// Initializes the platform interface with [id].
+  ///
+  /// This method is called when the plugin is first initialized.
+  @override
+  Future<void> init(int mapId) {
+    MethodChannel channel;
+    if (!_channels.containsKey(mapId)) {
+      channel = MethodChannel('plugins.flutter.io/google_maps_$mapId');
+      channel.setMethodCallHandler(
+          (MethodCall call) => _handleMethodCall(call, mapId));
+      _channels[mapId] = channel;
+    }
+    return channel.invokeMethod<void>('map#waitForMap');
+  }
+
+  // The controller we need to broadcast the different events coming
+  // from handleMethodCall.
+  //
+  // It is a `broadcast` because multiple controllers will connect to
+  // different stream views of this Controller.
+  final StreamController<MapEvent> _mapEventStreamController =
+      StreamController<MapEvent>.broadcast();
+
+  // Returns a filtered view of the events in the _controller, by mapId.
+  Stream<MapEvent> _events(int mapId) =>
+      _mapEventStreamController.stream.where((event) => event.mapId == mapId);
+
+  @override
+  Stream<CameraMoveStartedEvent> onCameraMoveStarted({@required int mapId}) {
+    return _events(mapId).whereType<CameraMoveStartedEvent>();
+  }
+
+  @override
+  Stream<CameraMoveEvent> onCameraMove({@required int mapId}) {
+    return _events(mapId).whereType<CameraMoveEvent>();
+  }
+
+  @override
+  Stream<CameraIdleEvent> onCameraIdle({@required int mapId}) {
+    return _events(mapId).whereType<CameraIdleEvent>();
+  }
+
+  @override
+  Stream<MarkerTapEvent> onMarkerTap({@required int mapId}) {
+    return _events(mapId).whereType<MarkerTapEvent>();
+  }
+
+  @override
+  Stream<InfoWindowTapEvent> onInfoWindowTap({@required int mapId}) {
+    return _events(mapId).whereType<InfoWindowTapEvent>();
+  }
+
+  @override
+  Stream<MarkerDragEndEvent> onMarkerDragEnd({@required int mapId}) {
+    return _events(mapId).whereType<MarkerDragEndEvent>();
+  }
+
+  @override
+  Stream<PolylineTapEvent> onPolylineTap({@required int mapId}) {
+    return _events(mapId).whereType<PolylineTapEvent>();
+  }
+
+  @override
+  Stream<PolygonTapEvent> onPolygonTap({@required int mapId}) {
+    return _events(mapId).whereType<PolygonTapEvent>();
+  }
+
+  @override
+  Stream<CircleTapEvent> onCircleTap({@required int mapId}) {
+    return _events(mapId).whereType<CircleTapEvent>();
+  }
+
+  @override
+  Stream<MapTapEvent> onTap({@required int mapId}) {
+    return _events(mapId).whereType<MapTapEvent>();
+  }
+
+  @override
+  Stream<MapLongPressEvent> onLongPress({@required int mapId}) {
+    return _events(mapId).whereType<MapLongPressEvent>();
+  }
+
+  Future<dynamic> _handleMethodCall(MethodCall call, int mapId) async {
+    switch (call.method) {
+      case 'camera#onMoveStarted':
+        _mapEventStreamController.add(CameraMoveStartedEvent(mapId));
+        break;
+      case 'camera#onMove':
+        _mapEventStreamController.add(CameraMoveEvent(
+          mapId,
+          CameraPosition.fromMap(call.arguments['position']),
+        ));
+        break;
+      case 'camera#onIdle':
+        _mapEventStreamController.add(CameraIdleEvent(mapId));
+        break;
+      case 'marker#onTap':
+        _mapEventStreamController.add(MarkerTapEvent(
+          mapId,
+          MarkerId(call.arguments['markerId']),
+        ));
+        break;
+      case 'marker#onDragEnd':
+        _mapEventStreamController.add(MarkerDragEndEvent(
+          mapId,
+          LatLng.fromJson(call.arguments['position']),
+          MarkerId(call.arguments['markerId']),
+        ));
+        break;
+      case 'infoWindow#onTap':
+        _mapEventStreamController.add(InfoWindowTapEvent(
+          mapId,
+          MarkerId(call.arguments['markerId']),
+        ));
+        break;
+      case 'polyline#onTap':
+        _mapEventStreamController.add(PolylineTapEvent(
+          mapId,
+          PolylineId(call.arguments['polylineId']),
+        ));
+        break;
+      case 'polygon#onTap':
+        _mapEventStreamController.add(PolygonTapEvent(
+          mapId,
+          PolygonId(call.arguments['polygonId']),
+        ));
+        break;
+      case 'circle#onTap':
+        _mapEventStreamController.add(CircleTapEvent(
+          mapId,
+          CircleId(call.arguments['circleId']),
+        ));
+        break;
+      case 'map#onTap':
+        _mapEventStreamController.add(MapTapEvent(
+          mapId,
+          LatLng.fromJson(call.arguments['position']),
+        ));
+        break;
+      case 'map#onLongPress':
+        _mapEventStreamController.add(MapLongPressEvent(
+          mapId,
+          LatLng.fromJson(call.arguments['position']),
+        ));
+        break;
+      default:
+        throw MissingPluginException();
+    }
+  }
+
+  /// Updates configuration options of the map user interface.
+  ///
+  /// Change listeners are notified once the update has been made on the
+  /// platform side.
+  ///
+  /// The returned [Future] completes after listeners have been notified.
+  @override
+  Future<void> updateMapOptions(
+    Map<String, dynamic> optionsUpdate, {
+    @required int mapId,
+  }) {
+    assert(optionsUpdate != null);
+    return channel(mapId).invokeMethod<void>(
+      'map#update',
+      <String, dynamic>{
+        'options': optionsUpdate,
+      },
+    );
+  }
+
+  /// Updates marker configuration.
+  ///
+  /// Change listeners are notified once the update has been made on the
+  /// platform side.
+  ///
+  /// The returned [Future] completes after listeners have been notified.
+  @override
+  Future<void> updateMarkers(
+    MarkerUpdates markerUpdates, {
+    @required int mapId,
+  }) {
+    assert(markerUpdates != null);
+    return channel(mapId).invokeMethod<void>(
+      'markers#update',
+      markerUpdates.toJson(),
+    );
+  }
+
+  /// Updates polygon configuration.
+  ///
+  /// Change listeners are notified once the update has been made on the
+  /// platform side.
+  ///
+  /// The returned [Future] completes after listeners have been notified.
+  @override
+  Future<void> updatePolygons(
+    PolygonUpdates polygonUpdates, {
+    @required int mapId,
+  }) {
+    assert(polygonUpdates != null);
+    return channel(mapId).invokeMethod<void>(
+      'polygons#update',
+      polygonUpdates.toJson(),
+    );
+  }
+
+  /// Updates polyline configuration.
+  ///
+  /// Change listeners are notified once the update has been made on the
+  /// platform side.
+  ///
+  /// The returned [Future] completes after listeners have been notified.
+  @override
+  Future<void> updatePolylines(
+    PolylineUpdates polylineUpdates, {
+    @required int mapId,
+  }) {
+    assert(polylineUpdates != null);
+    return channel(mapId).invokeMethod<void>(
+      'polylines#update',
+      polylineUpdates.toJson(),
+    );
+  }
+
+  /// Updates circle configuration.
+  ///
+  /// Change listeners are notified once the update has been made on the
+  /// platform side.
+  ///
+  /// The returned [Future] completes after listeners have been notified.
+  @override
+  Future<void> updateCircles(
+    CircleUpdates circleUpdates, {
+    @required int mapId,
+  }) {
+    assert(circleUpdates != null);
+    return channel(mapId).invokeMethod<void>(
+      'circles#update',
+      circleUpdates.toJson(),
+    );
+  }
+
+  /// Starts an animated change of the map camera position.
+  ///
+  /// The returned [Future] completes after the change has been started on the
+  /// platform side.
+  @override
+  Future<void> animateCamera(
+    CameraUpdate cameraUpdate, {
+    @required int mapId,
+  }) {
+    return channel(mapId)
+        .invokeMethod<void>('camera#animate', <String, dynamic>{
+      'cameraUpdate': cameraUpdate.toJson(),
+    });
+  }
+
+  /// Changes the map camera position.
+  ///
+  /// The returned [Future] completes after the change has been made on the
+  /// platform side.
+  @override
+  Future<void> moveCamera(
+    CameraUpdate cameraUpdate, {
+    @required int mapId,
+  }) {
+    return channel(mapId).invokeMethod<void>('camera#move', <String, dynamic>{
+      'cameraUpdate': cameraUpdate.toJson(),
+    });
+  }
+
+  /// Sets the styling of the base map.
+  ///
+  /// Set to `null` to clear any previous custom styling.
+  ///
+  /// If problems were detected with the [mapStyle], including un-parsable
+  /// styling JSON, unrecognized feature type, unrecognized element type, or
+  /// invalid styler keys: [MapStyleException] is thrown and the current
+  /// style is left unchanged.
+  ///
+  /// The style string can be generated using [map style tool](https://mapstyle.withgoogle.com/).
+  /// Also, refer [iOS](https://developers.google.com/maps/documentation/ios-sdk/style-reference)
+  /// and [Android](https://developers.google.com/maps/documentation/android-sdk/style-reference)
+  /// style reference for more information regarding the supported styles.
+  @override
+  Future<void> setMapStyle(
+    String mapStyle, {
+    @required int mapId,
+  }) async {
+    final List<dynamic> successAndError = await channel(mapId)
+        .invokeMethod<List<dynamic>>('map#setStyle', mapStyle);
+    final bool success = successAndError[0];
+    if (!success) {
+      throw MapStyleException(successAndError[1]);
+    }
+  }
+
+  /// Return the region that is visible in a map.
+  @override
+  Future<LatLngBounds> getVisibleRegion({
+    @required int mapId,
+  }) async {
+    final Map<String, dynamic> latLngBounds = await channel(mapId)
+        .invokeMapMethod<String, dynamic>('map#getVisibleRegion');
+    final LatLng southwest = LatLng.fromJson(latLngBounds['southwest']);
+    final LatLng northeast = LatLng.fromJson(latLngBounds['northeast']);
+
+    return LatLngBounds(northeast: northeast, southwest: southwest);
+  }
+
+  /// Return point [Map<String, int>] of the [screenCoordinateInJson] in the current map view.
+  ///
+  /// A projection is used to translate between on screen location and geographic coordinates.
+  /// Screen location is in screen pixels (not display pixels) with respect to the top left corner
+  /// of the map, not necessarily of the whole screen.
+  @override
+  Future<ScreenCoordinate> getScreenCoordinate(
+    LatLng latLng, {
+    @required int mapId,
+  }) async {
+    final Map<String, int> point = await channel(mapId)
+        .invokeMapMethod<String, int>(
+            'map#getScreenCoordinate', latLng.toJson());
+
+    return ScreenCoordinate(x: point['x'], y: point['y']);
+  }
+
+  /// Returns [LatLng] corresponding to the [ScreenCoordinate] in the current map view.
+  ///
+  /// Returned [LatLng] corresponds to a screen location. The screen location is specified in screen
+  /// pixels (not display pixels) relative to the top left of the map, not top left of the whole screen.
+  @override
+  Future<LatLng> getLatLng(
+    ScreenCoordinate screenCoordinate, {
+    @required int mapId,
+  }) async {
+    final List<dynamic> latLng = await channel(mapId)
+        .invokeMethod<List<dynamic>>(
+            'map#getLatLng', screenCoordinate.toJson());
+    return LatLng(latLng[0], latLng[1]);
+  }
+
+  /// Programmatically show the Info Window for a [Marker].
+  ///
+  /// The `markerId` must match one of the markers on the map.
+  /// An invalid `markerId` triggers an "Invalid markerId" error.
+  ///
+  /// * See also:
+  ///   * [hideMarkerInfoWindow] to hide the Info Window.
+  ///   * [isMarkerInfoWindowShown] to check if the Info Window is showing.
+  @override
+  Future<void> showMarkerInfoWindow(
+    MarkerId markerId, {
+    @required int mapId,
+  }) {
+    assert(markerId != null);
+    return channel(mapId).invokeMethod<void>(
+        'markers#showInfoWindow', <String, String>{'markerId': markerId.value});
+  }
+
+  /// Programmatically hide the Info Window for a [Marker].
+  ///
+  /// The `markerId` must match one of the markers on the map.
+  /// An invalid `markerId` triggers an "Invalid markerId" error.
+  ///
+  /// * See also:
+  ///   * [showMarkerInfoWindow] to show the Info Window.
+  ///   * [isMarkerInfoWindowShown] to check if the Info Window is showing.
+  @override
+  Future<void> hideMarkerInfoWindow(
+    MarkerId markerId, {
+    @required int mapId,
+  }) {
+    assert(markerId != null);
+    return channel(mapId).invokeMethod<void>(
+        'markers#hideInfoWindow', <String, String>{'markerId': markerId.value});
+  }
+
+  /// Returns `true` when the [InfoWindow] is showing, `false` otherwise.
+  ///
+  /// The `markerId` must match one of the markers on the map.
+  /// An invalid `markerId` triggers an "Invalid markerId" error.
+  ///
+  /// * See also:
+  ///   * [showMarkerInfoWindow] to show the Info Window.
+  ///   * [hideMarkerInfoWindow] to hide the Info Window.
+  @override
+  Future<bool> isMarkerInfoWindowShown(
+    MarkerId markerId, {
+    @required int mapId,
+  }) {
+    assert(markerId != null);
+    return channel(mapId).invokeMethod<bool>('markers#isInfoWindowShown',
+        <String, String>{'markerId': markerId.value});
+  }
+
+  /// Returns the current zoom level of the map
+  @override
+  Future<double> getZoomLevel({
+    @required int mapId,
+  }) {
+    return channel(mapId).invokeMethod<double>('map#getZoomLevel');
+  }
+
+  /// Returns the image bytes of the map
+  @override
+  Future<Uint8List> takeSnapshot({
+    @required int mapId,
+  }) {
+    return channel(mapId).invokeMethod<Uint8List>('map#takeSnapshot');
+  }
+
+  /// This method builds the appropriate platform view where the map
+  /// can be rendered.
+  /// The `mapId` is passed as a parameter from the framework on the
+  /// `onPlatformViewCreated` callback.
+  @override
+  Widget buildView(
+      Map<String, dynamic> creationParams,
+      Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizers,
+      PlatformViewCreatedCallback onPlatformViewCreated) {
+    if (defaultTargetPlatform == TargetPlatform.android) {
+      return AndroidView(
+        viewType: 'plugins.flutter.io/google_maps',
+        onPlatformViewCreated: onPlatformViewCreated,
+        gestureRecognizers: gestureRecognizers,
+        creationParams: creationParams,
+        creationParamsCodec: const StandardMessageCodec(),
+      );
+    } else if (defaultTargetPlatform == TargetPlatform.iOS) {
+      return UiKitView(
+        viewType: 'plugins.flutter.io/google_maps',
+        onPlatformViewCreated: onPlatformViewCreated,
+        gestureRecognizers: gestureRecognizers,
+        creationParams: creationParams,
+        creationParamsCodec: const StandardMessageCodec(),
+      );
+    }
+    return Text(
+        '$defaultTargetPlatform is not yet supported by the maps plugin');
+  }
+}
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/platform_interface/google_maps_flutter_platform.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/platform_interface/google_maps_flutter_platform.dart
new file mode 100644
index 000000000000..b89d3420c68e
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/platform_interface/google_maps_flutter_platform.dart
@@ -0,0 +1,314 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+import 'dart:typed_data';
+
+import 'package:flutter/widgets.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/gestures.dart';
+
+import 'package:google_maps_flutter_platform_interface/src/method_channel/method_channel_google_maps_flutter.dart';
+import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+
+/// The interface that platform-specific implementations of `google_maps_flutter` must extend.
+///
+/// Avoid `implements` of this interface. Using `implements` makes adding any new
+/// methods here a breaking change for end users of your platform!
+///
+/// Do `extends GoogleMapsFlutterPlatform` instead, so new methods added here are
+/// inherited in your code with the default implementation (that throws at runtime),
+/// rather than breaking your users at compile time.
+abstract class GoogleMapsFlutterPlatform extends PlatformInterface {
+  /// Constructs a GoogleMapsFlutterPlatform.
+  GoogleMapsFlutterPlatform() : super(token: _token);
+
+  static final Object _token = Object();
+
+  static GoogleMapsFlutterPlatform _instance = MethodChannelGoogleMapsFlutter();
+
+  /// The default instance of [GoogleMapsFlutterPlatform] to use.
+  ///
+  /// Defaults to [MethodChannelGoogleMapsFlutter].
+  static GoogleMapsFlutterPlatform get instance => _instance;
+
+  /// Platform-specific plugins should set this with their own platform-specific
+  /// class that extends [GoogleMapsFlutterPlatform] when they register themselves.
+  static set instance(GoogleMapsFlutterPlatform instance) {
+    PlatformInterface.verifyToken(instance, _token);
+    _instance = instance;
+  }
+
+  /// /// Initializes the platform interface with [id].
+  ///
+  /// This method is called when the plugin is first initialized.
+  Future<void> init(int mapId) {
+    throw UnimplementedError('init() has not been implemented.');
+  }
+
+  /// Updates configuration options of the map user interface.
+  ///
+  /// Change listeners are notified once the update has been made on the
+  /// platform side.
+  ///
+  /// The returned [Future] completes after listeners have been notified.
+  Future<void> updateMapOptions(
+    Map<String, dynamic> optionsUpdate, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError('updateMapOptions() has not been implemented.');
+  }
+
+  /// Updates marker configuration.
+  ///
+  /// Change listeners are notified once the update has been made on the
+  /// platform side.
+  ///
+  /// The returned [Future] completes after listeners have been notified.
+  Future<void> updateMarkers(
+    MarkerUpdates markerUpdates, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError('updateMarkers() has not been implemented.');
+  }
+
+  /// Updates polygon configuration.
+  ///
+  /// Change listeners are notified once the update has been made on the
+  /// platform side.
+  ///
+  /// The returned [Future] completes after listeners have been notified.
+  Future<void> updatePolygons(
+    PolygonUpdates polygonUpdates, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError('updatePolygons() has not been implemented.');
+  }
+
+  /// Updates polyline configuration.
+  ///
+  /// Change listeners are notified once the update has been made on the
+  /// platform side.
+  ///
+  /// The returned [Future] completes after listeners have been notified.
+  Future<void> updatePolylines(
+    PolylineUpdates polylineUpdates, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError('updatePolylines() has not been implemented.');
+  }
+
+  /// Updates circle configuration.
+  ///
+  /// Change listeners are notified once the update has been made on the
+  /// platform side.
+  ///
+  /// The returned [Future] completes after listeners have been notified.
+  Future<void> updateCircles(
+    CircleUpdates circleUpdates, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError('updateCircles() has not been implemented.');
+  }
+
+  /// Starts an animated change of the map camera position.
+  ///
+  /// The returned [Future] completes after the change has been started on the
+  /// platform side.
+  Future<void> animateCamera(
+    CameraUpdate cameraUpdate, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError('animateCamera() has not been implemented.');
+  }
+
+  /// Changes the map camera position.
+  ///
+  /// The returned [Future] completes after the change has been made on the
+  /// platform side.
+  Future<void> moveCamera(
+    CameraUpdate cameraUpdate, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError('moveCamera() has not been implemented.');
+  }
+
+  /// Sets the styling of the base map.
+  ///
+  /// Set to `null` to clear any previous custom styling.
+  ///
+  /// If problems were detected with the [mapStyle], including un-parsable
+  /// styling JSON, unrecognized feature type, unrecognized element type, or
+  /// invalid styler keys: [MapStyleException] is thrown and the current
+  /// style is left unchanged.
+  ///
+  /// The style string can be generated using [map style tool](https://mapstyle.withgoogle.com/).
+  Future<void> setMapStyle(
+    String mapStyle, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError('setMapStyle() has not been implemented.');
+  }
+
+  /// Return the region that is visible in a map.
+  Future<LatLngBounds> getVisibleRegion({
+    @required int mapId,
+  }) {
+    throw UnimplementedError('getVisibleRegion() has not been implemented.');
+  }
+
+  /// Return [ScreenCoordinate] of the [LatLng] in the current map view.
+  ///
+  /// A projection is used to translate between on screen location and geographic coordinates.
+  /// Screen location is in screen pixels (not display pixels) with respect to the top left corner
+  /// of the map, not necessarily of the whole screen.
+  Future<ScreenCoordinate> getScreenCoordinate(
+    LatLng latLng, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError('getScreenCoordinate() has not been implemented.');
+  }
+
+  /// Returns [LatLng] corresponding to the [ScreenCoordinate] in the current map view.
+  ///
+  /// A projection is used to translate between on screen location and geographic coordinates.
+  /// Screen location is in screen pixels (not display pixels) with respect to the top left corner
+  /// of the map, not necessarily of the whole screen.
+  Future<LatLng> getLatLng(
+    ScreenCoordinate screenCoordinate, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError('getLatLng() has not been implemented.');
+  }
+
+  /// Programmatically show the Info Window for a [Marker].
+  ///
+  /// The `markerId` must match one of the markers on the map.
+  /// An invalid `markerId` triggers an "Invalid markerId" error.
+  ///
+  /// * See also:
+  ///   * [hideMarkerInfoWindow] to hide the Info Window.
+  ///   * [isMarkerInfoWindowShown] to check if the Info Window is showing.
+  Future<void> showMarkerInfoWindow(
+    MarkerId markerId, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError(
+        'showMarkerInfoWindow() has not been implemented.');
+  }
+
+  /// Programmatically hide the Info Window for a [Marker].
+  ///
+  /// The `markerId` must match one of the markers on the map.
+  /// An invalid `markerId` triggers an "Invalid markerId" error.
+  ///
+  /// * See also:
+  ///   * [showMarkerInfoWindow] to show the Info Window.
+  ///   * [isMarkerInfoWindowShown] to check if the Info Window is showing.
+  Future<void> hideMarkerInfoWindow(
+    MarkerId markerId, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError(
+        'hideMarkerInfoWindow() has not been implemented.');
+  }
+
+  /// Returns `true` when the [InfoWindow] is showing, `false` otherwise.
+  ///
+  /// The `markerId` must match one of the markers on the map.
+  /// An invalid `markerId` triggers an "Invalid markerId" error.
+  ///
+  /// * See also:
+  ///   * [showMarkerInfoWindow] to show the Info Window.
+  ///   * [hideMarkerInfoWindow] to hide the Info Window.
+  Future<bool> isMarkerInfoWindowShown(
+    MarkerId markerId, {
+    @required int mapId,
+  }) {
+    throw UnimplementedError('updateMapOptions() has not been implemented.');
+  }
+
+  /// Returns the current zoom level of the map
+  Future<double> getZoomLevel({
+    @required int mapId,
+  }) {
+    throw UnimplementedError('getZoomLevel() has not been implemented.');
+  }
+
+  /// Returns the image bytes of the map
+  Future<Uint8List> takeSnapshot({
+    @required int mapId,
+  }) {
+    throw UnimplementedError('takeSnapshot() has not been implemented.');
+  }
+
+  // The following are the 11 possible streams of data from the native side
+  // into the plugin
+
+  /// The Camera started moving.
+  Stream<CameraMoveStartedEvent> onCameraMoveStarted({@required int mapId}) {
+    throw UnimplementedError('onCameraMoveStarted() has not been implemented.');
+  }
+
+  /// The Camera finished moving to a new [CameraPosition].
+  Stream<CameraMoveEvent> onCameraMove({@required int mapId}) {
+    throw UnimplementedError('onCameraMove() has not been implemented.');
+  }
+
+  /// The Camera is now idle.
+  Stream<CameraIdleEvent> onCameraIdle({@required int mapId}) {
+    throw UnimplementedError('onCameraMove() has not been implemented.');
+  }
+
+  /// A [Marker] has been tapped.
+  Stream<MarkerTapEvent> onMarkerTap({@required int mapId}) {
+    throw UnimplementedError('onMarkerTap() has not been implemented.');
+  }
+
+  /// An [InfoWindow] has been tapped.
+  Stream<InfoWindowTapEvent> onInfoWindowTap({@required int mapId}) {
+    throw UnimplementedError('onInfoWindowTap() has not been implemented.');
+  }
+
+  /// A [Marker] has been dragged to a different [LatLng] position.
+  Stream<MarkerDragEndEvent> onMarkerDragEnd({@required int mapId}) {
+    throw UnimplementedError('onMarkerDragEnd() has not been implemented.');
+  }
+
+  /// A [Polyline] has been tapped.
+  Stream<PolylineTapEvent> onPolylineTap({@required int mapId}) {
+    throw UnimplementedError('onPolylineTap() has not been implemented.');
+  }
+
+  /// A [Polygon] has been tapped.
+  Stream<PolygonTapEvent> onPolygonTap({@required int mapId}) {
+    throw UnimplementedError('onPolygonTap() has not been implemented.');
+  }
+
+  /// A [Circle] has been tapped.
+  Stream<CircleTapEvent> onCircleTap({@required int mapId}) {
+    throw UnimplementedError('onCircleTap() has not been implemented.');
+  }
+
+  /// A Map has been tapped at a certain [LatLng].
+  Stream<MapTapEvent> onTap({@required int mapId}) {
+    throw UnimplementedError('onTap() has not been implemented.');
+  }
+
+  /// A Map has been long-pressed at a certain [LatLng].
+  Stream<MapLongPressEvent> onLongPress({@required int mapId}) {
+    throw UnimplementedError('onLongPress() has not been implemented.');
+  }
+
+  /// Returns a widget displaying the map view
+  Widget buildView(
+      Map<String, dynamic> creationParams,
+      Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizers,
+      PlatformViewCreatedCallback onPlatformViewCreated) {
+    throw UnimplementedError('buildView() has not been implemented.');
+  }
+}
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/bitmap.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/bitmap.dart
similarity index 94%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/bitmap.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/bitmap.dart
index 7cf5b2e25b7e..40581b43e065 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/bitmap.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/bitmap.dart
@@ -2,7 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'dart:async' show Future;
+import 'dart:typed_data' show Uint8List;
+
+import 'package:flutter/material.dart'
+    show ImageConfiguration, AssetImage, AssetBundleImageKey;
+import 'package:flutter/services.dart' show AssetBundle;
 
 /// Defines a bitmap image. For a marker, this class can be used to set the
 /// image of the marker icon. For a ground overlay, it can be used to set the
@@ -107,9 +112,5 @@ class BitmapDescriptor {
   final dynamic _json;
 
   /// Convert the object to a Json format.
-  /// Used for testing only.
-  @visibleForTesting
   dynamic toJson() => _json;
-
-  dynamic _toJson() => _json;
 }
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/callbacks.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/callbacks.dart
similarity index 85%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/callbacks.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/callbacks.dart
index 284c7134cbfb..c20ece5d6c7c 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/callbacks.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/callbacks.dart
@@ -2,7 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'types.dart';
+
+/// Callback that receives updates to the camera position.
+///
+/// This callback is triggered when the platform Google Map
+/// registers a camera movement.
+///
+/// This is used in [GoogleMap.onCameraMove].
+typedef void CameraPositionCallback(CameraPosition position);
 
 /// Callback function taking a single argument.
 typedef void ArgumentCallback<T>(T argument);
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/camera.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/camera.dart
similarity index 93%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/camera.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/camera.dart
index 043d0f8c9d78..10ea1e98846a 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/camera.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/camera.dart
@@ -2,7 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'dart:ui' show hashValues, Offset;
+
+import 'package:meta/meta.dart' show required;
+
+import 'types.dart';
 
 /// The position of the map "camera", the view point from which the world is shown in the map view.
 ///
@@ -61,7 +65,7 @@ class CameraPosition {
   /// Mainly for internal use when calling [CameraUpdate.newCameraPosition].
   dynamic toMap() => <String, dynamic>{
         'bearing': bearing,
-        'target': target._toJson(),
+        'target': target.toJson(),
         'tilt': tilt,
         'zoom': zoom,
       };
@@ -75,7 +79,7 @@ class CameraPosition {
     }
     return CameraPosition(
       bearing: json['bearing'],
-      target: LatLng._fromJson(json['target']),
+      target: LatLng.fromJson(json['target']),
       tilt: json['tilt'],
       zoom: json['zoom'],
     );
@@ -115,7 +119,7 @@ class CameraUpdate {
   /// Returns a camera update that moves the camera target to the specified
   /// geographical location.
   static CameraUpdate newLatLng(LatLng latLng) {
-    return CameraUpdate._(<dynamic>['newLatLng', latLng._toJson()]);
+    return CameraUpdate._(<dynamic>['newLatLng', latLng.toJson()]);
   }
 
   /// Returns a camera update that transforms the camera so that the specified
@@ -125,7 +129,7 @@ class CameraUpdate {
   static CameraUpdate newLatLngBounds(LatLngBounds bounds, double padding) {
     return CameraUpdate._(<dynamic>[
       'newLatLngBounds',
-      bounds._toList(),
+      bounds.toJson(),
       padding,
     ]);
   }
@@ -134,7 +138,7 @@ class CameraUpdate {
   /// geographical location and zoom level.
   static CameraUpdate newLatLngZoom(LatLng latLng, double zoom) {
     return CameraUpdate._(
-      <dynamic>['newLatLngZoom', latLng._toJson(), zoom],
+      <dynamic>['newLatLngZoom', latLng.toJson(), zoom],
     );
   }
 
@@ -188,5 +192,6 @@ class CameraUpdate {
 
   final dynamic _json;
 
-  dynamic _toJson() => _json;
+  /// Converts this object to something serializable in JSON.
+  dynamic toJson() => _json;
 }
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/cap.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/cap.dart
similarity index 88%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/cap.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/cap.dart
index 1a6be1f3f528..68bf14c36408 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/cap.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/cap.dart
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'package:meta/meta.dart' show immutable;
+
+import 'types.dart';
 
 /// Cap that can be applied at the start or end vertex of a [Polyline].
 @immutable
@@ -43,10 +45,11 @@ class Cap {
   }) {
     assert(bitmapDescriptor != null);
     assert(refWidth > 0.0);
-    return Cap._(<dynamic>['customCap', bitmapDescriptor._toJson(), refWidth]);
+    return Cap._(<dynamic>['customCap', bitmapDescriptor.toJson(), refWidth]);
   }
 
   final dynamic _json;
 
-  dynamic _toJson() => _json;
+  /// Converts this object to something serializable in JSON.
+  dynamic toJson() => _json;
 }
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/circle.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/circle.dart
similarity index 89%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/circle.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/circle.dart
index 3edfc88ed4e0..d1418a4c30b1 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/circle.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/circle.dart
@@ -2,7 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'package:flutter/foundation.dart' show VoidCallback;
+import 'package:flutter/material.dart' show Color, Colors;
+import 'package:meta/meta.dart' show immutable, required;
+
+import 'types.dart';
 
 /// Uniquely identifies a [Circle] among [GoogleMap] circles.
 ///
@@ -119,7 +123,8 @@ class Circle {
   /// Creates a new [Circle] object whose values are the same as this instance.
   Circle clone() => copyWith();
 
-  dynamic _toJson() {
+  /// Converts this object to something serializable in JSON.
+  dynamic toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 
     void addIfPresent(String fieldName, dynamic value) {
@@ -131,7 +136,7 @@ class Circle {
     addIfPresent('circleId', circleId.value);
     addIfPresent('consumeTapEvents', consumeTapEvents);
     addIfPresent('fillColor', fillColor.value);
-    addIfPresent('center', center._toJson());
+    addIfPresent('center', center.toJson());
     addIfPresent('radius', radius);
     addIfPresent('strokeColor', strokeColor.value);
     addIfPresent('strokeWidth', strokeWidth);
@@ -160,18 +165,3 @@ class Circle {
   @override
   int get hashCode => circleId.hashCode;
 }
-
-Map<CircleId, Circle> _keyByCircleId(Iterable<Circle> circles) {
-  if (circles == null) {
-    return <CircleId, Circle>{};
-  }
-  return Map<CircleId, Circle>.fromEntries(circles.map((Circle circle) =>
-      MapEntry<CircleId, Circle>(circle.circleId, circle.clone())));
-}
-
-List<Map<String, dynamic>> _serializeCircleSet(Set<Circle> circles) {
-  if (circles == null) {
-    return null;
-  }
-  return circles.map<Map<String, dynamic>>((Circle p) => p._toJson()).toList();
-}
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/circle_updates.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/circle_updates.dart
similarity index 73%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/circle_updates.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/circle_updates.dart
index c977c4182c98..6f494423a38f 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/circle_updates.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/circle_updates.dart
@@ -2,14 +2,20 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'dart:ui' show hashValues;
+
+import 'package:flutter/foundation.dart' show setEquals;
+
+import 'types.dart';
+import 'utils/circle.dart';
 
 /// [Circle] update events to be applied to the [GoogleMap].
 ///
 /// Used in [GoogleMapController] when the map is updated.
-class _CircleUpdates {
-  /// Computes [_CircleUpdates] given previous and current [Circle]s.
-  _CircleUpdates.from(Set<Circle> previous, Set<Circle> current) {
+// (Do not re-export)
+class CircleUpdates {
+  /// Computes [CircleUpdates] given previous and current [Circle]s.
+  CircleUpdates.from(Set<Circle> previous, Set<Circle> current) {
     if (previous == null) {
       previous = Set<Circle>.identity();
     }
@@ -18,8 +24,8 @@ class _CircleUpdates {
       current = Set<Circle>.identity();
     }
 
-    final Map<CircleId, Circle> previousCircles = _keyByCircleId(previous);
-    final Map<CircleId, Circle> currentCircles = _keyByCircleId(current);
+    final Map<CircleId, Circle> previousCircles = keyByCircleId(previous);
+    final Map<CircleId, Circle> currentCircles = keyByCircleId(current);
 
     final Set<CircleId> prevCircleIds = previousCircles.keys.toSet();
     final Set<CircleId> currentCircleIds = currentCircles.keys.toSet();
@@ -54,11 +60,17 @@ class _CircleUpdates {
     circlesToChange = _circlesToChange;
   }
 
+  /// Set of Circles to be added in this update.
   Set<Circle> circlesToAdd;
+
+  /// Set of CircleIds to be removed in this update.
   Set<CircleId> circleIdsToRemove;
+
+  /// Set of Circles to be changed in this update.
   Set<Circle> circlesToChange;
 
-  Map<String, dynamic> _toMap() {
+  /// Converts this object to something serializable in JSON.
+  Map<String, dynamic> toJson() {
     final Map<String, dynamic> updateMap = <String, dynamic>{};
 
     void addIfNonNull(String fieldName, dynamic value) {
@@ -67,8 +79,8 @@ class _CircleUpdates {
       }
     }
 
-    addIfNonNull('circlesToAdd', _serializeCircleSet(circlesToAdd));
-    addIfNonNull('circlesToChange', _serializeCircleSet(circlesToChange));
+    addIfNonNull('circlesToAdd', serializeCircleSet(circlesToAdd));
+    addIfNonNull('circlesToChange', serializeCircleSet(circlesToChange));
     addIfNonNull('circleIdsToRemove',
         circleIdsToRemove.map<dynamic>((CircleId m) => m.value).toList());
 
@@ -79,7 +91,7 @@ class _CircleUpdates {
   bool operator ==(Object other) {
     if (identical(this, other)) return true;
     if (other.runtimeType != runtimeType) return false;
-    final _CircleUpdates typedOther = other;
+    final CircleUpdates typedOther = other;
     return setEquals(circlesToAdd, typedOther.circlesToAdd) &&
         setEquals(circleIdsToRemove, typedOther.circleIdsToRemove) &&
         setEquals(circlesToChange, typedOther.circlesToChange);
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/joint_type.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/joint_type.dart
similarity index 94%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/joint_type.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/joint_type.dart
index ced61ba77417..c7df0b298624 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/joint_type.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/joint_type.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'package:meta/meta.dart' show immutable;
 
 /// Joint types for [Polyline].
 @immutable
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/location.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/location.dart
similarity index 87%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/location.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/location.dart
index ae299ce9583d..6b76a6d496ac 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/location.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/location.dart
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'dart:ui' show hashValues;
+
+import 'package:meta/meta.dart';
 
 /// A pair of latitude and longitude coordinates, stored as degrees.
 class LatLng {
@@ -26,11 +28,13 @@ class LatLng {
   /// The longitude in degrees between -180.0 (inclusive) and 180.0 (exclusive).
   final double longitude;
 
-  dynamic _toJson() {
+  /// Converts this object to something serializable in JSON.
+  dynamic toJson() {
     return <double>[latitude, longitude];
   }
 
-  static LatLng _fromJson(dynamic json) {
+  /// Initialize a LatLng from an \[lat, lng\] array.
+  static LatLng fromJson(dynamic json) {
     if (json == null) {
       return null;
     }
@@ -73,8 +77,9 @@ class LatLngBounds {
   /// The northeast corner of the rectangle.
   final LatLng northeast;
 
-  dynamic _toList() {
-    return <dynamic>[southwest._toJson(), northeast._toJson()];
+  /// Converts this object to something serializable in JSON.
+  dynamic toJson() {
+    return <dynamic>[southwest.toJson(), northeast.toJson()];
   }
 
   /// Returns whether this rectangle contains the given [LatLng].
@@ -102,8 +107,8 @@ class LatLngBounds {
       return null;
     }
     return LatLngBounds(
-      southwest: LatLng._fromJson(json[0]),
-      northeast: LatLng._fromJson(json[1]),
+      southwest: LatLng.fromJson(json[0]),
+      northeast: LatLng.fromJson(json[1]),
     );
   }
 
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/marker.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/marker.dart
similarity index 94%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/marker.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/marker.dart
index 480f0a379c1e..9b57f9676334 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/marker.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/marker.dart
@@ -2,7 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'dart:ui' show hashValues, Offset;
+
+import 'package:flutter/foundation.dart' show ValueChanged, VoidCallback;
+import 'package:meta/meta.dart' show immutable, required;
+
+import 'types.dart';
 
 dynamic _offsetToJson(Offset offset) {
   if (offset == null) {
@@ -262,7 +267,8 @@ class Marker {
   /// Creates a new [Marker] object whose values are the same as this instance.
   Marker clone() => copyWith();
 
-  Map<String, dynamic> _toJson() {
+  /// Converts this object to something serializable in JSON.
+  Map<String, dynamic> toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 
     void addIfPresent(String fieldName, dynamic value) {
@@ -277,9 +283,9 @@ class Marker {
     addIfPresent('consumeTapEvents', consumeTapEvents);
     addIfPresent('draggable', draggable);
     addIfPresent('flat', flat);
-    addIfPresent('icon', icon?._toJson());
+    addIfPresent('icon', icon?.toJson());
     addIfPresent('infoWindow', infoWindow?._toJson());
-    addIfPresent('position', position?._toJson());
+    addIfPresent('position', position?.toJson());
     addIfPresent('rotation', rotation);
     addIfPresent('visible', visible);
     addIfPresent('zIndex', zIndex);
@@ -316,18 +322,3 @@ class Marker {
         'visible: $visible, zIndex: $zIndex, onTap: $onTap}';
   }
 }
-
-Map<MarkerId, Marker> _keyByMarkerId(Iterable<Marker> markers) {
-  if (markers == null) {
-    return <MarkerId, Marker>{};
-  }
-  return Map<MarkerId, Marker>.fromEntries(markers.map((Marker marker) =>
-      MapEntry<MarkerId, Marker>(marker.markerId, marker.clone())));
-}
-
-List<Map<String, dynamic>> _serializeMarkerSet(Set<Marker> markers) {
-  if (markers == null) {
-    return null;
-  }
-  return markers.map<Map<String, dynamic>>((Marker m) => m._toJson()).toList();
-}
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/marker_updates.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/marker_updates.dart
similarity index 73%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/marker_updates.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/marker_updates.dart
index d4a08255e069..bb6ea8813ea3 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/marker_updates.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/marker_updates.dart
@@ -2,14 +2,20 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'dart:ui' show hashValues;
+
+import 'package:flutter/foundation.dart' show setEquals;
+
+import 'types.dart';
+import 'utils/marker.dart';
 
 /// [Marker] update events to be applied to the [GoogleMap].
 ///
 /// Used in [GoogleMapController] when the map is updated.
-class _MarkerUpdates {
-  /// Computes [_MarkerUpdates] given previous and current [Marker]s.
-  _MarkerUpdates.from(Set<Marker> previous, Set<Marker> current) {
+// (Do not re-export)
+class MarkerUpdates {
+  /// Computes [MarkerUpdates] given previous and current [Marker]s.
+  MarkerUpdates.from(Set<Marker> previous, Set<Marker> current) {
     if (previous == null) {
       previous = Set<Marker>.identity();
     }
@@ -18,8 +24,8 @@ class _MarkerUpdates {
       current = Set<Marker>.identity();
     }
 
-    final Map<MarkerId, Marker> previousMarkers = _keyByMarkerId(previous);
-    final Map<MarkerId, Marker> currentMarkers = _keyByMarkerId(current);
+    final Map<MarkerId, Marker> previousMarkers = keyByMarkerId(previous);
+    final Map<MarkerId, Marker> currentMarkers = keyByMarkerId(current);
 
     final Set<MarkerId> prevMarkerIds = previousMarkers.keys.toSet();
     final Set<MarkerId> currentMarkerIds = currentMarkers.keys.toSet();
@@ -54,11 +60,17 @@ class _MarkerUpdates {
     markersToChange = _markersToChange;
   }
 
+  /// Set of Markers to be added in this update.
   Set<Marker> markersToAdd;
+
+  /// Set of MarkerIds to be removed in this update.
   Set<MarkerId> markerIdsToRemove;
+
+  /// Set of Markers to be changed in this update.
   Set<Marker> markersToChange;
 
-  Map<String, dynamic> _toMap() {
+  /// Converts this object to something serializable in JSON.
+  Map<String, dynamic> toJson() {
     final Map<String, dynamic> updateMap = <String, dynamic>{};
 
     void addIfNonNull(String fieldName, dynamic value) {
@@ -67,8 +79,8 @@ class _MarkerUpdates {
       }
     }
 
-    addIfNonNull('markersToAdd', _serializeMarkerSet(markersToAdd));
-    addIfNonNull('markersToChange', _serializeMarkerSet(markersToChange));
+    addIfNonNull('markersToAdd', serializeMarkerSet(markersToAdd));
+    addIfNonNull('markersToChange', serializeMarkerSet(markersToChange));
     addIfNonNull('markerIdsToRemove',
         markerIdsToRemove.map<dynamic>((MarkerId m) => m.value).toList());
 
@@ -79,7 +91,7 @@ class _MarkerUpdates {
   bool operator ==(Object other) {
     if (identical(this, other)) return true;
     if (other.runtimeType != runtimeType) return false;
-    final _MarkerUpdates typedOther = other;
+    final MarkerUpdates typedOther = other;
     return setEquals(markersToAdd, typedOther.markersToAdd) &&
         setEquals(markerIdsToRemove, typedOther.markerIdsToRemove) &&
         setEquals(markersToChange, typedOther.markersToChange);
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/pattern_item.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/pattern_item.dart
similarity index 86%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/pattern_item.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/pattern_item.dart
index 82e8703d10e2..28c7ce9d33dd 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/pattern_item.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/pattern_item.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'package:meta/meta.dart' show immutable;
 
 /// Item used in the stroke pattern for a Polyline.
 @immutable
@@ -30,5 +30,6 @@ class PatternItem {
 
   final dynamic _json;
 
-  dynamic _toJson() => _json;
+  /// Converts this object to something serializable in JSON.
+  dynamic toJson() => _json;
 }
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/polygon.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polygon.dart
similarity index 90%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/polygon.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polygon.dart
index 973667eece09..3b5e25060faf 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/polygon.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polygon.dart
@@ -2,7 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'package:flutter/foundation.dart' show listEquals, VoidCallback;
+import 'package:flutter/material.dart' show Color, Colors;
+import 'package:meta/meta.dart' show immutable, required;
+
+import 'types.dart';
 
 /// Uniquely identifies a [Polygon] among [GoogleMap] polygons.
 ///
@@ -127,7 +131,8 @@ class Polygon {
     return copyWith(pointsParam: List<LatLng>.of(points));
   }
 
-  dynamic _toJson() {
+  /// Converts this object to something serializable in JSON.
+  dynamic toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 
     void addIfPresent(String fieldName, dynamic value) {
@@ -174,25 +179,8 @@ class Polygon {
   dynamic _pointsToJson() {
     final List<dynamic> result = <dynamic>[];
     for (final LatLng point in points) {
-      result.add(point._toJson());
+      result.add(point.toJson());
     }
     return result;
   }
 }
-
-Map<PolygonId, Polygon> _keyByPolygonId(Iterable<Polygon> polygons) {
-  if (polygons == null) {
-    return <PolygonId, Polygon>{};
-  }
-  return Map<PolygonId, Polygon>.fromEntries(polygons.map((Polygon polygon) =>
-      MapEntry<PolygonId, Polygon>(polygon.polygonId, polygon.clone())));
-}
-
-List<Map<String, dynamic>> _serializePolygonSet(Set<Polygon> polygons) {
-  if (polygons == null) {
-    return null;
-  }
-  return polygons
-      .map<Map<String, dynamic>>((Polygon p) => p._toJson())
-      .toList();
-}
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/polygon_updates.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polygon_updates.dart
similarity index 73%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/polygon_updates.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polygon_updates.dart
index 5a14c6b8ec5c..cc8b8e26c896 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/polygon_updates.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polygon_updates.dart
@@ -2,14 +2,20 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'dart:ui' show hashValues;
+
+import 'package:flutter/foundation.dart' show setEquals;
+
+import 'types.dart';
+import 'utils/polygon.dart';
 
 /// [Polygon] update events to be applied to the [GoogleMap].
 ///
 /// Used in [GoogleMapController] when the map is updated.
-class _PolygonUpdates {
-  /// Computes [_PolygonUpdates] given previous and current [Polygon]s.
-  _PolygonUpdates.from(Set<Polygon> previous, Set<Polygon> current) {
+// (Do not re-export)
+class PolygonUpdates {
+  /// Computes [PolygonUpdates] given previous and current [Polygon]s.
+  PolygonUpdates.from(Set<Polygon> previous, Set<Polygon> current) {
     if (previous == null) {
       previous = Set<Polygon>.identity();
     }
@@ -18,8 +24,8 @@ class _PolygonUpdates {
       current = Set<Polygon>.identity();
     }
 
-    final Map<PolygonId, Polygon> previousPolygons = _keyByPolygonId(previous);
-    final Map<PolygonId, Polygon> currentPolygons = _keyByPolygonId(current);
+    final Map<PolygonId, Polygon> previousPolygons = keyByPolygonId(previous);
+    final Map<PolygonId, Polygon> currentPolygons = keyByPolygonId(current);
 
     final Set<PolygonId> prevPolygonIds = previousPolygons.keys.toSet();
     final Set<PolygonId> currentPolygonIds = currentPolygons.keys.toSet();
@@ -54,11 +60,17 @@ class _PolygonUpdates {
     polygonsToChange = _polygonsToChange;
   }
 
+  /// Set of Polygons to be added in this update.
   Set<Polygon> polygonsToAdd;
+
+  /// Set of PolygonIds to be removed in this update.
   Set<PolygonId> polygonIdsToRemove;
+
+  /// Set of Polygons to be changed in this update.
   Set<Polygon> polygonsToChange;
 
-  Map<String, dynamic> _toMap() {
+  /// Converts this object to something serializable in JSON.
+  Map<String, dynamic> toJson() {
     final Map<String, dynamic> updateMap = <String, dynamic>{};
 
     void addIfNonNull(String fieldName, dynamic value) {
@@ -67,8 +79,8 @@ class _PolygonUpdates {
       }
     }
 
-    addIfNonNull('polygonsToAdd', _serializePolygonSet(polygonsToAdd));
-    addIfNonNull('polygonsToChange', _serializePolygonSet(polygonsToChange));
+    addIfNonNull('polygonsToAdd', serializePolygonSet(polygonsToAdd));
+    addIfNonNull('polygonsToChange', serializePolygonSet(polygonsToChange));
     addIfNonNull('polygonIdsToRemove',
         polygonIdsToRemove.map<dynamic>((PolygonId m) => m.value).toList());
 
@@ -79,7 +91,7 @@ class _PolygonUpdates {
   bool operator ==(Object other) {
     if (identical(this, other)) return true;
     if (other.runtimeType != runtimeType) return false;
-    final _PolygonUpdates typedOther = other;
+    final PolygonUpdates typedOther = other;
     return setEquals(polygonsToAdd, typedOther.polygonsToAdd) &&
         setEquals(polygonIdsToRemove, typedOther.polygonIdsToRemove) &&
         setEquals(polygonsToChange, typedOther.polygonsToChange);
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/polyline.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polyline.dart
similarity index 90%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/polyline.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polyline.dart
index c27b19e2843e..ae5c3b976352 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/polyline.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polyline.dart
@@ -2,7 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'package:flutter/foundation.dart' show listEquals, VoidCallback;
+import 'package:flutter/material.dart' show Color, Colors;
+import 'package:meta/meta.dart' show immutable, required;
+
+import 'types.dart';
 
 /// Uniquely identifies a [Polyline] among [GoogleMap] polylines.
 ///
@@ -169,7 +173,8 @@ class Polyline {
     );
   }
 
-  dynamic _toJson() {
+  /// Converts this object to something serializable in JSON.
+  dynamic toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 
     void addIfPresent(String fieldName, dynamic value) {
@@ -181,10 +186,10 @@ class Polyline {
     addIfPresent('polylineId', polylineId.value);
     addIfPresent('consumeTapEvents', consumeTapEvents);
     addIfPresent('color', color.value);
-    addIfPresent('endCap', endCap?._toJson());
+    addIfPresent('endCap', endCap?.toJson());
     addIfPresent('geodesic', geodesic);
     addIfPresent('jointType', jointType?.value);
-    addIfPresent('startCap', startCap?._toJson());
+    addIfPresent('startCap', startCap?.toJson());
     addIfPresent('visible', visible);
     addIfPresent('width', width);
     addIfPresent('zIndex', zIndex);
@@ -225,7 +230,7 @@ class Polyline {
   dynamic _pointsToJson() {
     final List<dynamic> result = <dynamic>[];
     for (final LatLng point in points) {
-      result.add(point._toJson());
+      result.add(point.toJson());
     }
     return result;
   }
@@ -234,27 +239,9 @@ class Polyline {
     final List<dynamic> result = <dynamic>[];
     for (final PatternItem patternItem in patterns) {
       if (patternItem != null) {
-        result.add(patternItem._toJson());
+        result.add(patternItem.toJson());
       }
     }
     return result;
   }
 }
-
-Map<PolylineId, Polyline> _keyByPolylineId(Iterable<Polyline> polylines) {
-  if (polylines == null) {
-    return <PolylineId, Polyline>{};
-  }
-  return Map<PolylineId, Polyline>.fromEntries(polylines.map(
-      (Polyline polyline) => MapEntry<PolylineId, Polyline>(
-          polyline.polylineId, polyline.clone())));
-}
-
-List<Map<String, dynamic>> _serializePolylineSet(Set<Polyline> polylines) {
-  if (polylines == null) {
-    return null;
-  }
-  return polylines
-      .map<Map<String, dynamic>>((Polyline p) => p._toJson())
-      .toList();
-}
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/polyline_updates.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polyline_updates.dart
similarity index 74%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/polyline_updates.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polyline_updates.dart
index ed972a51c8bf..f871928c0ac4 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/polyline_updates.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polyline_updates.dart
@@ -2,14 +2,20 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'dart:ui' show hashValues;
+
+import 'package:flutter/foundation.dart' show setEquals;
+
+import 'utils/polyline.dart';
+import 'types.dart';
 
 /// [Polyline] update events to be applied to the [GoogleMap].
 ///
 /// Used in [GoogleMapController] when the map is updated.
-class _PolylineUpdates {
-  /// Computes [_PolylineUpdates] given previous and current [Polyline]s.
-  _PolylineUpdates.from(Set<Polyline> previous, Set<Polyline> current) {
+// (Do not re-export)
+class PolylineUpdates {
+  /// Computes [PolylineUpdates] given previous and current [Polyline]s.
+  PolylineUpdates.from(Set<Polyline> previous, Set<Polyline> current) {
     if (previous == null) {
       previous = Set<Polyline>.identity();
     }
@@ -19,9 +25,8 @@ class _PolylineUpdates {
     }
 
     final Map<PolylineId, Polyline> previousPolylines =
-        _keyByPolylineId(previous);
-    final Map<PolylineId, Polyline> currentPolylines =
-        _keyByPolylineId(current);
+        keyByPolylineId(previous);
+    final Map<PolylineId, Polyline> currentPolylines = keyByPolylineId(current);
 
     final Set<PolylineId> prevPolylineIds = previousPolylines.keys.toSet();
     final Set<PolylineId> currentPolylineIds = currentPolylines.keys.toSet();
@@ -56,11 +61,17 @@ class _PolylineUpdates {
     polylinesToChange = _polylinesToChange;
   }
 
+  /// Set of Polylines to be added in this update.
   Set<Polyline> polylinesToAdd;
+
+  /// Set of PolylineIds to be removed in this update.
   Set<PolylineId> polylineIdsToRemove;
+
+  /// Set of Polylines to be changed in this update.
   Set<Polyline> polylinesToChange;
 
-  Map<String, dynamic> _toMap() {
+  /// Converts this object to something serializable in JSON.
+  Map<String, dynamic> toJson() {
     final Map<String, dynamic> updateMap = <String, dynamic>{};
 
     void addIfNonNull(String fieldName, dynamic value) {
@@ -69,8 +80,8 @@ class _PolylineUpdates {
       }
     }
 
-    addIfNonNull('polylinesToAdd', _serializePolylineSet(polylinesToAdd));
-    addIfNonNull('polylinesToChange', _serializePolylineSet(polylinesToChange));
+    addIfNonNull('polylinesToAdd', serializePolylineSet(polylinesToAdd));
+    addIfNonNull('polylinesToChange', serializePolylineSet(polylinesToChange));
     addIfNonNull('polylineIdsToRemove',
         polylineIdsToRemove.map<dynamic>((PolylineId m) => m.value).toList());
 
@@ -81,7 +92,7 @@ class _PolylineUpdates {
   bool operator ==(Object other) {
     if (identical(this, other)) return true;
     if (other.runtimeType != runtimeType) return false;
-    final _PolylineUpdates typedOther = other;
+    final PolylineUpdates typedOther = other;
     return setEquals(polylinesToAdd, typedOther.polylinesToAdd) &&
         setEquals(polylineIdsToRemove, typedOther.polylineIdsToRemove) &&
         setEquals(polylinesToChange, typedOther.polylinesToChange);
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/screen_coordinate.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/screen_coordinate.dart
similarity index 86%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/screen_coordinate.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/screen_coordinate.dart
index e58abe9cefad..965db7969bc2 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/screen_coordinate.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/screen_coordinate.dart
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'dart:ui' show hashValues;
+
+import 'package:meta/meta.dart' show immutable, required;
 
 /// Represents a point coordinate in the [GoogleMap]'s view.
 ///
@@ -23,7 +25,8 @@ class ScreenCoordinate {
   /// Represents the number of pixels from the top of the [GoogleMap].
   final int y;
 
-  dynamic _toJson() {
+  /// Converts this object to something serializable in JSON.
+  dynamic toJson() {
     return <String, int>{
       "x": x,
       "y": y,
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/types.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/types.dart
new file mode 100644
index 000000000000..e56c3a5dd646
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/types.dart
@@ -0,0 +1,28 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// All the public types exposed by this package.
+export 'bitmap.dart';
+export 'callbacks.dart';
+export 'camera.dart';
+export 'cap.dart';
+export 'circle_updates.dart';
+export 'circle.dart';
+export 'joint_type.dart';
+export 'location.dart';
+export 'marker_updates.dart';
+export 'marker.dart';
+export 'pattern_item.dart';
+export 'polygon_updates.dart';
+export 'polygon.dart';
+export 'polyline_updates.dart';
+export 'polyline.dart';
+export 'screen_coordinate.dart';
+export 'ui.dart';
+
+// Export the utils, they're used by the Widget
+export 'utils/circle.dart';
+export 'utils/marker.dart';
+export 'utils/polygon.dart';
+export 'utils/polyline.dart';
diff --git a/packages/google_maps_flutter/google_maps_flutter/lib/src/ui.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/ui.dart
similarity index 92%
rename from packages/google_maps_flutter/google_maps_flutter/lib/src/ui.dart
rename to packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/ui.dart
index 4b57ebd7440f..8d84171bac03 100644
--- a/packages/google_maps_flutter/google_maps_flutter/lib/src/ui.dart
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/ui.dart
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of google_maps_flutter;
+import 'dart:ui' show hashValues;
+
+import 'types.dart';
 
 /// Type of map tiles to display.
 // Enum constants must be indexed to match the corresponding int constants of
@@ -42,7 +44,8 @@ class CameraTargetBounds {
   /// Unbounded camera target.
   static const CameraTargetBounds unbounded = CameraTargetBounds(null);
 
-  dynamic _toJson() => <dynamic>[bounds?._toList()];
+  /// Converts this object to something serializable in JSON.
+  dynamic toJson() => <dynamic>[bounds?.toJson()];
 
   @override
   bool operator ==(dynamic other) {
@@ -82,7 +85,8 @@ class MinMaxZoomPreference {
   static const MinMaxZoomPreference unbounded =
       MinMaxZoomPreference(null, null);
 
-  dynamic _toJson() => <dynamic>[minZoom, maxZoom];
+  /// Converts this object to something serializable in JSON.
+  dynamic toJson() => <dynamic>[minZoom, maxZoom];
 
   @override
   bool operator ==(dynamic other) {
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/circle.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/circle.dart
new file mode 100644
index 000000000000..5c3af96f8e02
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/circle.dart
@@ -0,0 +1,22 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import '../types.dart';
+
+/// Converts an [Iterable] of Circles in a Map of CircleId -> Circle.
+Map<CircleId, Circle> keyByCircleId(Iterable<Circle> circles) {
+  if (circles == null) {
+    return <CircleId, Circle>{};
+  }
+  return Map<CircleId, Circle>.fromEntries(circles.map((Circle circle) =>
+      MapEntry<CircleId, Circle>(circle.circleId, circle.clone())));
+}
+
+/// Converts a Set of Circles into something serializable in JSON.
+List<Map<String, dynamic>> serializeCircleSet(Set<Circle> circles) {
+  if (circles == null) {
+    return null;
+  }
+  return circles.map<Map<String, dynamic>>((Circle p) => p.toJson()).toList();
+}
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/marker.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/marker.dart
new file mode 100644
index 000000000000..7a2c76d8055b
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/marker.dart
@@ -0,0 +1,22 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import '../types.dart';
+
+/// Converts an [Iterable] of Markers in a Map of MarkerId -> Marker.
+Map<MarkerId, Marker> keyByMarkerId(Iterable<Marker> markers) {
+  if (markers == null) {
+    return <MarkerId, Marker>{};
+  }
+  return Map<MarkerId, Marker>.fromEntries(markers.map((Marker marker) =>
+      MapEntry<MarkerId, Marker>(marker.markerId, marker.clone())));
+}
+
+/// Converts a Set of Markers into something serializable in JSON.
+List<Map<String, dynamic>> serializeMarkerSet(Set<Marker> markers) {
+  if (markers == null) {
+    return null;
+  }
+  return markers.map<Map<String, dynamic>>((Marker m) => m.toJson()).toList();
+}
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/polygon.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/polygon.dart
new file mode 100644
index 000000000000..9434ddaa077d
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/polygon.dart
@@ -0,0 +1,22 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import '../types.dart';
+
+/// Converts an [Iterable] of Polygons in a Map of PolygonId -> Polygon.
+Map<PolygonId, Polygon> keyByPolygonId(Iterable<Polygon> polygons) {
+  if (polygons == null) {
+    return <PolygonId, Polygon>{};
+  }
+  return Map<PolygonId, Polygon>.fromEntries(polygons.map((Polygon polygon) =>
+      MapEntry<PolygonId, Polygon>(polygon.polygonId, polygon.clone())));
+}
+
+/// Converts a Set of Polygons into something serializable in JSON.
+List<Map<String, dynamic>> serializePolygonSet(Set<Polygon> polygons) {
+  if (polygons == null) {
+    return null;
+  }
+  return polygons.map<Map<String, dynamic>>((Polygon p) => p.toJson()).toList();
+}
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/polyline.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/polyline.dart
new file mode 100644
index 000000000000..9cef6319ddb5
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/polyline.dart
@@ -0,0 +1,25 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import '../types.dart';
+
+/// Converts an [Iterable] of Polylines in a Map of PolylineId -> Polyline.
+Map<PolylineId, Polyline> keyByPolylineId(Iterable<Polyline> polylines) {
+  if (polylines == null) {
+    return <PolylineId, Polyline>{};
+  }
+  return Map<PolylineId, Polyline>.fromEntries(polylines.map(
+      (Polyline polyline) => MapEntry<PolylineId, Polyline>(
+          polyline.polylineId, polyline.clone())));
+}
+
+/// Converts a Set of Polylines into something serializable in JSON.
+List<Map<String, dynamic>> serializePolylineSet(Set<Polyline> polylines) {
+  if (polylines == null) {
+    return null;
+  }
+  return polylines
+      .map<Map<String, dynamic>>((Polyline p) => p.toJson())
+      .toList();
+}
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/pubspec.yaml b/packages/google_maps_flutter/google_maps_flutter_platform_interface/pubspec.yaml
new file mode 100644
index 000000000000..2cd840b07e3a
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/pubspec.yaml
@@ -0,0 +1,23 @@
+name: google_maps_flutter_platform_interface
+description: A common platform interface for the google_maps_flutter plugin.
+homepage: https://github.com/flutter/plugins/tree/master/packages/google_maps_flutter/google_maps_flutter_platform_interface
+# NOTE: We strongly prefer non-breaking changes, even at the expense of a
+# less-clean API. See https://flutter.dev/go/platform-interface-breaking-changes
+version: 1.0.0
+
+dependencies:
+  flutter:
+    sdk: flutter
+  meta: ^1.0.5
+  plugin_platform_interface: ^1.0.1
+  stream_transform: ^1.2.0
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  mockito: ^4.1.1
+  pedantic: ^1.8.0
+
+environment:
+  sdk: ">=2.0.0-dev.28.0 <3.0.0"
+  flutter: ">=1.9.1+hotfix.4 <2.0.0"
diff --git a/packages/google_maps_flutter/google_maps_flutter_platform_interface/test/platform_interface/google_maps_flutter_platform_test.dart b/packages/google_maps_flutter/google_maps_flutter_platform_interface/test/platform_interface/google_maps_flutter_platform_test.dart
new file mode 100644
index 000000000000..a003b94d544c
--- /dev/null
+++ b/packages/google_maps_flutter/google_maps_flutter_platform_interface/test/platform_interface/google_maps_flutter_platform_test.dart
@@ -0,0 +1,71 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:mockito/mockito.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+
+import 'package:google_maps_flutter_platform_interface/src/method_channel/method_channel_google_maps_flutter.dart';
+import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platform_interface.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  group('$GoogleMapsFlutterPlatform', () {
+    test('$MethodChannelGoogleMapsFlutter() is the default instance', () {
+      expect(GoogleMapsFlutterPlatform.instance,
+          isInstanceOf<MethodChannelGoogleMapsFlutter>());
+    });
+
+    test('Cannot be implemented with `implements`', () {
+      expect(() {
+        GoogleMapsFlutterPlatform.instance =
+            ImplementsGoogleMapsFlutterPlatform();
+      }, throwsA(isInstanceOf<AssertionError>()));
+    });
+
+    test('Can be mocked with `implements`', () {
+      final GoogleMapsFlutterPlatformMock mock =
+          GoogleMapsFlutterPlatformMock();
+      GoogleMapsFlutterPlatform.instance = mock;
+    });
+
+    test('Can be extended', () {
+      GoogleMapsFlutterPlatform.instance = ExtendsGoogleMapsFlutterPlatform();
+    });
+  });
+
+  group('$MethodChannelGoogleMapsFlutter', () {
+    const MethodChannel channel =
+        MethodChannel('plugins.flutter.io/google_maps_flutter');
+    final List<MethodCall> log = <MethodCall>[];
+    channel.setMockMethodCallHandler((MethodCall methodCall) async {
+      log.add(methodCall);
+    });
+
+//    final MethodChannelGoogleMapsFlutter map = MethodChannelGoogleMapsFlutter(0);
+
+    tearDown(() {
+      log.clear();
+    });
+
+    test('foo', () async {
+//      await map.foo();
+      expect(
+        log,
+        <Matcher>[],
+      );
+    });
+  });
+}
+
+class GoogleMapsFlutterPlatformMock extends Mock
+    with MockPlatformInterfaceMixin
+    implements GoogleMapsFlutterPlatform {}
+
+class ImplementsGoogleMapsFlutterPlatform extends Mock
+    implements GoogleMapsFlutterPlatform {}
+
+class ExtendsGoogleMapsFlutterPlatform extends GoogleMapsFlutterPlatform {}