Enable hybrid composition by default on Android

common/settings.h

@@ -223,15 +223,6 @@ struct Settings {
   /// to log a timeline event that tracks the latency of engine startup.
   std::chrono::microseconds engine_start_timestamp = {};
 
-  /// Whether the application claims that it uses the android embedded view for
-  /// platform views.
-  ///
-  /// A `true` value will result the raster task runner always run on the
-  /// platform thread.
-  // TODO(cyanlaz): Remove this when dynamic thread merging is done.
-  // https://github.com/flutter/flutter/issues/59930
-  bool use_embedded_view = false;
-
   std::string ToString() const;
 };
 

flow/surface.cc

@@ -18,4 +18,8 @@ std::unique_ptr<GLContextResult> Surface::MakeRenderContextCurrent() {
   return std::make_unique<GLContextDefaultResult>(true);
 }
 
+bool Surface::ClearRenderContext() {
+  return false;
+}
+
 }  // namespace flutter

flow/surface.h

@@ -33,6 +33,8 @@ class Surface {
 
   virtual std::unique_ptr<GLContextResult> MakeRenderContextCurrent();
 
+  virtual bool ClearRenderContext();
+
  private:
   FML_DISALLOW_COPY_AND_ASSIGN(Surface);
 };

shell/common/rasterizer.cc

@@ -143,6 +143,10 @@ void Rasterizer::Draw(fml::RefPtr<Pipeline<flutter::LayerTree>> pipeline) {
     consume_result = PipelineConsumeResult::MoreAvailable;
   }
 
+  if (surface_ != nullptr) {
+    surface_->ClearRenderContext();
+  }
+
   // Merging the thread as we know the next `Draw` should be run on the platform
   // thread.
   if (surface_ != nullptr && surface_->GetExternalViewEmbedder() != nullptr) {

shell/common/switches.cc

@@ -229,9 +229,6 @@ Settings SettingsFromCommandLine(const fml::CommandLine& command_line) {
                                                             : "127.0.0.1";
   }
 
-  settings.use_embedded_view =
-      command_line.HasOption(FlagForSwitch(Switch::UseEmbeddedView));
-
   // Set Observatory Port
   if (command_line.HasOption(FlagForSwitch(Switch::DeviceObservatoryPort))) {
     if (!GetSwitchValue(command_line, Switch::DeviceObservatoryPort,

shell/common/switches.h

@@ -196,15 +196,7 @@ DEF_SWITCH(
     "Uses separate threads for the platform, UI, GPU and IO task runners. "
     "By default, a single thread is used for all task runners. Only available "
     "in the flutter_tester.")
-// TODO(cyanlaz): Remove this when dynamic thread merging is done.
-// https://github.com/flutter/flutter/issues/59930
-DEF_SWITCH(UseEmbeddedView,
-           "use-embedded-view",
-           "Whether an android application uses embedded views."
-           "This is a temporary flag to make the raster task runner runs on "
-           "the platform thread."
-           "This flag should be removed once the dynamic thread merging is "
-           "enabled on android.")
+
 DEF_SWITCHES_END
 
 void PrintUsage(const std::string& executable_name);

shell/gpu/gpu_surface_gl.cc

@@ -341,4 +341,9 @@ std::unique_ptr<GLContextResult> GPUSurfaceGL::MakeRenderContextCurrent() {
   return delegate_->GLContextMakeCurrent();
 }
 
+// |Surface|
+bool GPUSurfaceGL::ClearRenderContext() {
+  return delegate_->GLContextClearCurrent();
+}
+
 }  // namespace flutter

shell/gpu/gpu_surface_gl.h

@@ -48,6 +48,9 @@ class GPUSurfaceGL : public Surface {
   // |Surface|
   std::unique_ptr<GLContextResult> MakeRenderContextCurrent() override;
 
+  // |Surface|
+  bool ClearRenderContext() override;
+
  private:
   GPUSurfaceGLDelegate* delegate_;
   sk_sp<GrDirectContext> context_;

shell/platform/android/android_shell_holder.cc

@@ -28,8 +28,6 @@ static PlatformData GetDefaultPlatformData() {
   return platform_data;
 }
 
-bool AndroidShellHolder::use_embedded_view;
-
 AndroidShellHolder::AndroidShellHolder(
     flutter::Settings settings,
     std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
@@ -102,47 +100,21 @@ AndroidShellHolder::AndroidShellHolder(
     ui_runner = thread_host_.ui_thread->GetTaskRunner();
     io_runner = thread_host_.io_thread->GetTaskRunner();
   }
-  if (settings.use_embedded_view) {
-    use_embedded_view = true;
-    // Embedded views requires the gpu and the platform views to be the same.
-    // The plan is to eventually dynamically merge the threads when there's a
-    // platform view in the layer tree.
-    // For now we use a fixed thread configuration with the same thread used as
-    // the gpu and platform task runner.
-    // TODO(amirh/chinmaygarde): remove this, and dynamically change the thread
-    // configuration. https://github.com/flutter/flutter/issues/23975
-    // https://github.com/flutter/flutter/issues/59930
-    flutter::TaskRunners task_runners(thread_label,     // label
-                                      platform_runner,  // platform
-                                      platform_runner,  // raster
-                                      ui_runner,        // ui
-                                      io_runner         // io
-    );
-
-    shell_ =
-        Shell::Create(task_runners,              // task runners
-                      GetDefaultPlatformData(),  // window data
-                      settings_,                 // settings
-                      on_create_platform_view,  // platform view create callback
-                      on_create_rasterizer      // rasterizer create callback
-        );
-  } else {
-    use_embedded_view = false;
-    flutter::TaskRunners task_runners(thread_label,     // label
-                                      platform_runner,  // platform
-                                      gpu_runner,       // raster
-                                      ui_runner,        // ui
-                                      io_runner         // io
-    );
-
-    shell_ =
-        Shell::Create(task_runners,              // task runners
-                      GetDefaultPlatformData(),  // window data
-                      settings_,                 // settings
-                      on_create_platform_view,  // platform view create callback
-                      on_create_rasterizer      // rasterizer create callback
-        );
-  }
+
+  flutter::TaskRunners task_runners(thread_label,     // label
+                                    platform_runner,  // platform
+                                    gpu_runner,       // raster
+                                    ui_runner,        // ui
+                                    io_runner         // io
+  );
+
+  shell_ =
+      Shell::Create(task_runners,              // task runners
+                    GetDefaultPlatformData(),  // window data
+                    settings_,                 // settings
+                    on_create_platform_view,   // platform view create callback
+                    on_create_rasterizer       // rasterizer create callback
+      );
 
   platform_view_ = weak_platform_view;
   FML_DCHECK(platform_view_);

shell/platform/android/android_shell_holder.h

@@ -21,14 +21,6 @@ namespace flutter {
 
 class AndroidShellHolder {
  public:
-  // Whether the application sets to use embedded_view view
-  // `io.flutter.embedded_views_preview` flag. This can be static because it is
-  // determined by the application and it is safe when there are multiple
-  // `AndroidSurface`s.
-  // TODO(cyanglaz): remove this when dynamic thread merging is enabled on
-  // android. https://github.com/flutter/flutter/issues/59930
-  static bool use_embedded_view;
-
   AndroidShellHolder(flutter::Settings settings,
                      std::shared_ptr<PlatformViewAndroidJNI> jni_facade,
                      bool is_background_view);

shell/platform/android/android_surface_gl.cc

@@ -123,9 +123,6 @@ intptr_t AndroidSurfaceGL::GLContextFBO(GLFrameInfo frame_info) const {
 
 // |GPUSurfaceGLDelegate|
 ExternalViewEmbedder* AndroidSurfaceGL::GetExternalViewEmbedder() {
-  if (!AndroidShellHolder::use_embedded_view) {
-    return nullptr;
-  }
   return external_view_embedder_.get();
 }
 

shell/platform/android/android_surface_software.cc

@@ -146,9 +146,6 @@ bool AndroidSurfaceSoftware::PresentBackingStore(
 
 // |GPUSurfaceSoftwareDelegate|
 ExternalViewEmbedder* AndroidSurfaceSoftware::GetExternalViewEmbedder() {
-  if (!AndroidShellHolder::use_embedded_view) {
-    return nullptr;
-  }
   return external_view_embedder_.get();
 }
 

shell/platform/android/io/flutter/embedding/engine/loader/ApplicationInfoLoader.java

@@ -79,11 +79,6 @@ private static String getNetworkPolicy(ApplicationInfo appInfo, Context context)
     return output.toString();
   }
 
-  private static boolean getUseEmbeddedView(ApplicationInfo appInfo) {
-    Bundle bundle = appInfo.metaData;
-    return bundle != null && bundle.getBoolean("io.flutter.embedded_views_preview");
-  }
-
   private static void parseDomainConfig(
       XmlResourceParser xrp, JSONArray output, boolean inheritedCleartextPermitted)
       throws IOException, XmlPullParserException {
@@ -155,7 +150,6 @@ public static FlutterApplicationInfo load(@NonNull Context applicationContext) {
         getString(appInfo.metaData, PUBLIC_FLUTTER_ASSETS_DIR_KEY),
         getNetworkPolicy(appInfo, applicationContext),
         appInfo.nativeLibraryDir,
-        clearTextPermitted,
-        getUseEmbeddedView(appInfo));
+        clearTextPermitted);
   }
 }

shell/platform/android/io/flutter/embedding/engine/loader/FlutterApplicationInfo.java

@@ -18,9 +18,6 @@ public final class FlutterApplicationInfo {
   final String domainNetworkPolicy;
   final String nativeLibraryDir;
   final boolean clearTextPermitted;
-  // TODO(cyanlaz): Remove this when dynamic thread merging is done.
-  // https://github.com/flutter/flutter/issues/59930
-  final boolean useEmbeddedView;
 
   public FlutterApplicationInfo(
       String aotSharedLibraryName,
@@ -29,8 +26,7 @@ public FlutterApplicationInfo(
       String flutterAssetsDir,
       String domainNetworkPolicy,
       String nativeLibraryDir,
-      boolean clearTextPermitted,
-      boolean useEmbeddedView) {
+      boolean clearTextPermitted) {
     this.aotSharedLibraryName =
         aotSharedLibraryName == null ? DEFAULT_AOT_SHARED_LIBRARY_NAME : aotSharedLibraryName;
     this.vmSnapshotData = vmSnapshotData == null ? DEFAULT_VM_SNAPSHOT_DATA : vmSnapshotData;
@@ -41,6 +37,5 @@ public FlutterApplicationInfo(
     this.nativeLibraryDir = nativeLibraryDir;
     this.domainNetworkPolicy = domainNetworkPolicy == null ? "" : domainNetworkPolicy;
     this.clearTextPermitted = clearTextPermitted;
-    this.useEmbeddedView = useEmbeddedView;
   }
 }

shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java

@@ -223,9 +223,6 @@ public void ensureInitializationComplete(
       if (flutterApplicationInfo.domainNetworkPolicy != null) {
         shellArgs.add("--domain-network-policy=" + flutterApplicationInfo.domainNetworkPolicy);
       }
-      if (flutterApplicationInfo.useEmbeddedView) {
-        shellArgs.add("--use-embedded-view");
-      }
       if (settings.getLogTag() != null) {
         shellArgs.add("--log-tag=" + settings.getLogTag());
       }

shell/platform/android/test/io/flutter/embedding/engine/PluginComponentTest.java

@@ -28,7 +28,7 @@ public void pluginsCanAccessFlutterAssetPaths() {
     FlutterJNI flutterJNI = mock(FlutterJNI.class);
     when(flutterJNI.isAttached()).thenReturn(true);
     FlutterApplicationInfo emptyInfo =
-        new FlutterApplicationInfo(null, null, null, null, null, null, false, false);
+        new FlutterApplicationInfo(null, null, null, null, null, null, false);
 
     // FlutterLoader is the object to which the PluginRegistry defers for obtaining
     // the path to a Flutter asset. Ideally in this component test we would use a

shell/platform/android/test/io/flutter/embedding/engine/loader/ApplicationInfoLoaderTest.java

@@ -43,7 +43,6 @@ public void itGeneratesCorrectApplicationInfoWithDefaultManifest() {
     assertEquals("", info.domainNetworkPolicy);
     assertNull(info.nativeLibraryDir);
     assertEquals(true, info.clearTextPermitted);
-    assertEquals(false, info.useEmbeddedView);
   }
 
   @Config(shadows = {ApplicationInfoLoaderTest.ShadowNetworkSecurityPolicy.class})
@@ -88,7 +87,6 @@ public void itGeneratesCorrectApplicationInfoWithCustomValues() throws Exception
     bundle.putString(ApplicationInfoLoader.PUBLIC_VM_SNAPSHOT_DATA_KEY, "testvmsnapshot");
     bundle.putString(ApplicationInfoLoader.PUBLIC_ISOLATE_SNAPSHOT_DATA_KEY, "testisolatesnapshot");
     bundle.putString(ApplicationInfoLoader.PUBLIC_FLUTTER_ASSETS_DIR_KEY, "testassets");
-    bundle.putBoolean("io.flutter.embedded_views_preview", true);
     Context context = generateMockContext(bundle, null);
     FlutterApplicationInfo info = ApplicationInfoLoader.load(context);
     assertNotNull(info);
@@ -98,7 +96,6 @@ public void itGeneratesCorrectApplicationInfoWithCustomValues() throws Exception
     assertEquals("testassets", info.flutterAssetsDir);
     assertNull(info.nativeLibraryDir);
     assertEquals("", info.domainNetworkPolicy);
-    assertEquals(true, info.useEmbeddedView);
   }
 
   @Test

testing/scenario_app/android/app/src/main/AndroidManifest.xml

@@ -35,9 +35,6 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-        <meta-data
-            android:name="io.flutter.embedded_views_preview"
-            android:value="true" />
     </application>
     <uses-permission android:name="android.permission.INTERNET" />
 </manifest>