Destroy overlay surfaces when the rasterizer is torn down

flow/embedded_views.cc

@@ -64,4 +64,6 @@ bool ExternalViewEmbedder::SupportsDynamicThreadMerging() {
   return false;
 }
 
+void ExternalViewEmbedder::Teardown() {}
+
 }  // namespace flutter

flow/embedded_views.h

@@ -337,6 +337,11 @@ class ExternalViewEmbedder {
   // |RasterThreadMerger| instance.
   virtual bool SupportsDynamicThreadMerging();
 
+  // Called when the rasterizer is being torn down.
+  // This method provides a way to release resources associated with the current
+  // embedder.
+  virtual void Teardown();
+
   FML_DISALLOW_COPY_AND_ASSIGN(ExternalViewEmbedder);
 
 };  // ExternalViewEmbedder

shell/common/rasterizer.cc

@@ -97,6 +97,10 @@ void Rasterizer::Teardown() {
     raster_thread_merger_->UnMergeNowIfLastOne();
     raster_thread_merger_->SetMergeUnmergeCallback(nullptr);
   }
+
+  if (external_view_embedder_) {
+    external_view_embedder_->Teardown();
+  }
 }
 
 void Rasterizer::EnableThreadMergerIfNeeded() {

shell/platform/android/external_view_embedder/external_view_embedder.cc

@@ -298,4 +298,9 @@ bool AndroidExternalViewEmbedder::SupportsDynamicThreadMerging() {
   return true;
 }
 
+// |ExternalViewEmbedder|
+void AndroidExternalViewEmbedder::Teardown() {
+  surface_pool_->DestroyLayers(jni_facade_);
+}
+
 }  // namespace flutter

shell/platform/android/external_view_embedder/external_view_embedder.h

@@ -73,6 +73,8 @@ class AndroidExternalViewEmbedder final : public ExternalViewEmbedder {
 
   bool SupportsDynamicThreadMerging() override;
 
+  void Teardown() override;
+
   // Gets the rect based on the device pixel ratio of a platform view displayed
   // on the screen.
   SkRect GetViewRect(int view_id) const;

shell/platform/android/external_view_embedder/external_view_embedder_unittests.cc

@@ -883,5 +883,70 @@ TEST(AndroidExternalViewEmbedder, DisableThreadMerger) {
   ASSERT_FALSE(raster_thread_merger->IsMerged());
 }
 
+TEST(AndroidExternalViewEmbedder, Teardown) {
+  auto jni_mock = std::make_shared<JNIMock>();
+  auto android_context =
+      std::make_shared<AndroidContext>(AndroidRenderingAPI::kSoftware);
+  auto window = fml::MakeRefCounted<AndroidNativeWindow>(nullptr);
+  auto gr_context = GrDirectContext::MakeMock(nullptr);
+  auto frame_size = SkISize::Make(1000, 1000);
+  auto surface_factory = std::make_shared<TestAndroidSurfaceFactory>(
+      [&android_context, gr_context, window, frame_size]() {
+        auto surface_frame_1 = std::make_unique<SurfaceFrame>(
+            SkSurface::MakeNull(1000, 1000), false,
+            [](const SurfaceFrame& surface_frame, SkCanvas* canvas) {
+              return true;
+            });
+
+        auto surface_mock = std::make_unique<SurfaceMock>();
+        EXPECT_CALL(*surface_mock, AcquireFrame(frame_size))
+            .WillOnce(Return(ByMove(std::move(surface_frame_1))));
+
+        auto android_surface_mock =
+            std::make_unique<AndroidSurfaceMock>(android_context);
+        EXPECT_CALL(*android_surface_mock, IsValid()).WillOnce(Return(true));
+        EXPECT_CALL(*android_surface_mock, CreateGPUSurface(gr_context.get()))
+            .WillOnce(Return(ByMove(std::move(surface_mock))));
+
+        return android_surface_mock;
+      });
+
+  auto embedder = std::make_unique<AndroidExternalViewEmbedder>(
+      *android_context, jni_mock, surface_factory);
+  fml::Thread rasterizer_thread("rasterizer");
+  auto raster_thread_merger =
+      GetThreadMergerFromPlatformThread(&rasterizer_thread);
+
+  embedder->BeginFrame(frame_size, nullptr, 1.5, raster_thread_merger);
+
+  // Add an Android view.
+  MutatorsStack stack;
+  auto view_params = std::make_unique<EmbeddedViewParams>(
+      SkMatrix(), SkSize::Make(200, 200), stack);
+
+  embedder->PrerollCompositeEmbeddedView(0, std::move(view_params));
+
+  // This simulates Flutter UI that intersects with the Android view.
+  embedder->CompositeEmbeddedView(0)->drawRect(
+      SkRect::MakeXYWH(50, 50, 200, 200), SkPaint());
+
+  // Create a new overlay surface.
+  EXPECT_CALL(*jni_mock, FlutterViewCreateOverlaySurface())
+      .WillOnce(Return(
+          ByMove(std::make_unique<PlatformViewAndroidJNI::OverlayMetadata>(
+              0, window))));
+
+  auto surface_frame = std::make_unique<SurfaceFrame>(
+      SkSurface::MakeNull(1000, 1000), false,
+      [](const SurfaceFrame& surface_frame, SkCanvas* canvas) { return true; });
+  embedder->SubmitFrame(gr_context.get(), std::move(surface_frame));
+
+  embedder->EndFrame(/*should_resubmit_frame=*/false, raster_thread_merger);
+
+  EXPECT_CALL(*jni_mock, FlutterViewDestroyOverlaySurfaces());
+  // Teardown.
+  embedder->Teardown();
+}
+
 }  // namespace testing
 }  // namespace flutter