Bug 1387920 - Drop all ImageContainers' ImageClients during disabling WebRender r=nical

gfx/layers/ImageContainer.cpp

@@ -135,6 +135,16 @@ ImageContainer::GetImageClient()
   return imageClient.forget();
 }
 
+void
+ImageContainer::DropImageClient()
+{
+  RecursiveMutexAutoLock mon(mRecursiveMutex);
+  if (mImageClient) {
+    mImageClient->ClearCachedResources();
+    mImageClient = nullptr;
+  }
+}
+
 void
 ImageContainer::EnsureImageClient()
 {

gfx/layers/ImageContainer.h

@@ -618,6 +618,8 @@ public:
    */
   static ProducerID AllocateProducerID();
 
+  void DropImageClient();
+
 private:
   typedef mozilla::RecursiveMutex RecursiveMutex;
 

gfx/layers/ipc/ImageBridgeChild.cpp

@@ -726,7 +726,24 @@ MessageLoop * ImageBridgeChild::GetMessageLoop() const
 ImageBridgeChild::IdentifyCompositorTextureHost(const TextureFactoryIdentifier& aIdentifier)
 {
   if (RefPtr<ImageBridgeChild> child = GetSingleton()) {
-    child->IdentifyTextureHost(aIdentifier);
+    child->UpdateTextureFactoryIdentifier(aIdentifier);
+  }
+}
+
+void
+ImageBridgeChild::UpdateTextureFactoryIdentifier(const TextureFactoryIdentifier& aIdentifier)
+{
+  bool disablingWebRender = GetCompositorBackendType() == LayersBackend::LAYERS_WR &&
+                            aIdentifier.mParentBackend != LayersBackend::LAYERS_WR;
+  IdentifyTextureHost(aIdentifier);
+  if (disablingWebRender) {
+    // ImageHost is incompatible between WebRender enabled and WebRender disabled.
+    // Then drop all ImageContainers' ImageClients during disabling WebRender.
+    MutexAutoLock lock(mContainerMapLock);
+    for (auto iter = mImageContainers.Iter(); !iter.Done(); iter.Next()) {
+      ImageContainer* container = iter.Data();
+      container->DropImageClient();
+    }
   }
 }
 

gfx/layers/ipc/ImageBridgeChild.h

@@ -250,6 +250,8 @@ private:
   void ProxyAllocShmemNow(SynchronousTask* aTask, AllocShmemParams* aParams);
   void ProxyDeallocShmemNow(SynchronousTask* aTask, Shmem* aShmem, bool* aResult);
 
+  void UpdateTextureFactoryIdentifier(const TextureFactoryIdentifier& aIdentifier);
+
 public:
   // CompositableForwarder