[web] Librarify keyboard files

lib/web_ui/lib/src/engine.dart

@@ -93,6 +93,14 @@ export 'engine/html/shaders/vertex_shaders.dart';
 
 export 'engine/html/shaders/webgl_context.dart';
 
+import 'engine/keyboard_binding.dart';
+export 'engine/keyboard_binding.dart';
+
+import 'engine/keyboard.dart';
+export 'engine/keyboard.dart';
+
+export 'engine/key_map.dart';
+
 import 'engine/mouse_cursor.dart';
 export 'engine/mouse_cursor.dart';
 
@@ -243,9 +251,6 @@ part 'engine/html/shader_mask.dart';
 part 'engine/html/surface.dart';
 part 'engine/html/surface_stats.dart';
 part 'engine/html/transform.dart';
-part 'engine/keyboard_binding.dart';
-part 'engine/keyboard.dart';
-part 'engine/key_map.dart';
 part 'engine/onscreen_logging.dart';
 part 'engine/picture.dart';
 part 'engine/platform_dispatcher.dart';

lib/web_ui/lib/src/engine/key_map.dart

@@ -9,8 +9,6 @@
 // Edit the template dev/tools/gen_keycodes/data/web_key_map_dart.tmpl instead.
 // See dev/tools/gen_keycodes/README.md for more information.
 
-part of engine;
-
 /// Maps Web KeyboardEvent codes to the matching LogicalKeyboardKey id.
 const Map<String, int> kWebToLogicalKey = <String, int>{
   'None': 0x0000000000,

lib/web_ui/lib/src/engine/keyboard.dart

@@ -2,7 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of engine;
+import 'dart:async';
+import 'dart:html' as html;
+import 'dart:typed_data';
+
+import 'package:ui/src/engine.dart' show EnginePlatformDispatcher, registerHotRestartListener;
+
+import 'services.dart';
 
 /// After a keydown is received, this is the duration we wait for a repeat event
 /// before we decide to synthesize a keyup event.

lib/web_ui/lib/src/engine/keyboard_binding.dart

@@ -2,7 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-part of engine;
+import 'dart:html' as html;
+
+import 'package:ui/src/engine.dart' show EnginePlatformDispatcher, EngineSemanticsOwner, registerHotRestartListener;
+import 'package:ui/ui.dart' as ui;
+
+import 'browser_detection.dart';
+import 'key_map.dart';
 
 typedef _VoidCallback = void Function();
 typedef ValueGetter<T> = T Function();

lib/web_ui/test/keyboard_converter_test.dart

@@ -5,7 +5,7 @@
 import 'package:quiver/testing/async.dart';
 import 'package:test/bootstrap/browser.dart';
 import 'package:test/test.dart';
-import 'package:ui/src/engine.dart';
+import 'package:ui/src/engine/keyboard_binding.dart';
 import 'package:ui/ui.dart' as ui;
 import 'package:meta/meta.dart' show isTest;
 

lib/web_ui/test/keyboard_test.dart

@@ -9,7 +9,10 @@ import 'dart:typed_data';
 import 'package:quiver/testing/async.dart';
 import 'package:test/bootstrap/browser.dart';
 import 'package:test/test.dart';
-import 'package:ui/src/engine.dart';
+import 'package:ui/src/engine/browser_detection.dart';
+import 'package:ui/src/engine/keyboard.dart';
+import 'package:ui/src/engine/services.dart';
+import 'package:ui/src/engine.dart' show HybridTextEditing;
 import 'package:ui/ui.dart' as ui;
 
 void main() {