Fixing flakiness of TextureLayerChangeInvisibleMailboxTest

cc/trees/proxy_impl.h

Index: cc/trees/proxy_impl.h
diff --git a/cc/trees/proxy_impl.h b/cc/trees/proxy_impl.h
index a0482ea2ff89449a7c97249c20c24457d919c318..fb0e9f7e51d3ef34c1c0a4582cb1b9660b198f48 100644
--- a/cc/trees/proxy_impl.h
+++ b/cc/trees/proxy_impl.h
@@ -34,7 +34,8 @@ class CC_EXPORT ProxyImpl : public NON_EXPORTED_BASE(LayerTreeHostImplClient),
                                         BrowserControlsState current,
                                         bool animate);
   void InitializeCompositorFrameSinkOnImpl(
-      CompositorFrameSink* compositor_frame_sink);
+      CompositorFrameSink* compositor_frame_sink,
+      base::WeakPtr<ProxyMain> compositor_frame_sink_weak_ptr);
   void InitializeMutatorOnImpl(std::unique_ptr<LayerTreeMutator> mutator);
   void MainThreadHasStoppedFlingingOnImpl();
   void SetInputThrottledUntilCommitOnImpl(bool is_throttled);
@@ -147,6 +148,10 @@ class CC_EXPORT ProxyImpl : public NON_EXPORTED_BASE(LayerTreeHostImplClient),
   // Used to post tasks to ProxyMain on the main thread.
   base::WeakPtr<ProxyMain> proxy_main_weak_ptr_;
 
+  // A weak pointer to ProxyMain that is invalidated when CompositorFrameSink is
+  // released.
+  base::WeakPtr<ProxyMain> compositor_frame_sink_weak_ptr_;
+
   DISALLOW_COPY_AND_ASSIGN(ProxyImpl);
 };