Cherry picks for image decoding in Impeller

impeller/renderer/backend/metal/render_pass_mtl.mm

@@ -383,10 +383,13 @@ static bool Bind(PassBindingsCache& pass,
   }
 
   if (texture.NeedsMipmapGeneration()) {
+    // TODO(127697): generate mips when the GPU is available on iOS.
+#if !FML_OS_IOS
     VALIDATION_LOG
         << "Texture at binding index " << bind_index
         << " has a mip count > 1, but the mipmap has not been generated.";
     return false;
+#endif  // !FML_OS_IOS
   }
 
   return pass.SetTexture(stage, bind_index,

lib/ui/fixtures/ui_test.dart

@@ -248,12 +248,12 @@ void createPath() {
 external void _validatePath(Path path);
 
 @pragma('vm:entry-point')
-void frameCallback(Object? image, int durationMilliseconds) {
-  validateFrameCallback(image, durationMilliseconds);
+void frameCallback(Object? image, int durationMilliseconds, String decodeError) {
+  validateFrameCallback(image, durationMilliseconds, decodeError);
 }
 
 @pragma('vm:external-name', 'ValidateFrameCallback')
-external void validateFrameCallback(Object? image, int durationMilliseconds);
+external void validateFrameCallback(Object? image, int durationMilliseconds, String decodeError);
 
 @pragma('vm:entry-point')
 void platformMessagePortResponseTest() async {

lib/ui/painting.dart

@@ -2105,9 +2105,12 @@ class Codec extends NativeFieldWrapperClass1 {
   /// [FrameInfo.image] on the returned object.
   Future<FrameInfo> getNextFrame() async {
     final Completer<FrameInfo> completer = Completer<FrameInfo>.sync();
-    final String? error = _getNextFrame((_Image? image, int durationMilliseconds) {
+    final String? error = _getNextFrame((_Image? image, int durationMilliseconds, String decodeError) {
       if (image == null) {
-        completer.completeError(Exception('Codec failed to produce an image, possibly due to invalid image data.'));
+        if (decodeError.isEmpty) {
+          decodeError = 'Codec failed to produce an image, possibly due to invalid image data.';
+        }
+        completer.completeError(Exception(decodeError));
       } else {
         completer.complete(FrameInfo._(
           image: Image._(image, image.width, image.height),
@@ -2123,7 +2126,7 @@ class Codec extends NativeFieldWrapperClass1 {
 
   /// Returns an error message on failure, null on success.
   @Native<Handle Function(Pointer<Void>, Handle)>(symbol: 'Codec::getNextFrame')
-  external String? _getNextFrame(void Function(_Image?, int) callback);
+  external String? _getNextFrame(void Function(_Image?, int, String) callback);
 
   /// Release the resources used by this object. The object is no longer usable
   /// after this method is called.

lib/ui/painting/image_decoder.cc

@@ -16,14 +16,16 @@ std::unique_ptr<ImageDecoder> ImageDecoder::Make(
     const Settings& settings,
     const TaskRunners& runners,
     std::shared_ptr<fml::ConcurrentTaskRunner> concurrent_task_runner,
-    fml::WeakPtr<IOManager> io_manager) {
+    fml::WeakPtr<IOManager> io_manager,
+    const std::shared_ptr<fml::SyncSwitch>& gpu_disabled_switch) {
 #if IMPELLER_SUPPORTS_RENDERING
   if (settings.enable_impeller) {
     return std::make_unique<ImageDecoderImpeller>(
         runners,                            //
         std::move(concurrent_task_runner),  //
         std::move(io_manager),              //
-        settings.enable_wide_gamut);
+        settings.enable_wide_gamut,         //
+        gpu_disabled_switch);
   }
 #endif  // IMPELLER_SUPPORTS_RENDERING
   return std::make_unique<ImageDecoderSkia>(

lib/ui/painting/image_decoder.h

@@ -27,11 +27,12 @@ class ImageDecoder {
       const Settings& settings,
       const TaskRunners& runners,
       std::shared_ptr<fml::ConcurrentTaskRunner> concurrent_task_runner,
-      fml::WeakPtr<IOManager> io_manager);
+      fml::WeakPtr<IOManager> io_manager,
+      const std::shared_ptr<fml::SyncSwitch>& gpu_disabled_switch);
 
   virtual ~ImageDecoder();
 
-  using ImageResult = std::function<void(sk_sp<DlImage>)>;
+  using ImageResult = std::function<void(sk_sp<DlImage>, std::string)>;
 
   // Takes an image descriptor and returns a handle to a texture resident on the
   // GPU. All image decompression and resizes are done on a worker thread