Fixing flakiness of TextureLayerChangeInvisibleMailboxTest

cc/trees/proxy_impl.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TREES_PROXY_IMPL_H_
 #define CC_TREES_PROXY_IMPL_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 16 matching lines @@
  public:
   ProxyImpl(base::WeakPtr<ProxyMain> proxy_main_weak_ptr,
             LayerTreeHost* layer_tree_host,
             TaskRunnerProvider* task_runner_provider);
   ~ProxyImpl() override;
 
   void UpdateBrowserControlsStateOnImpl(BrowserControlsState constraints,
                                         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);
   void SetDeferCommitsOnImpl(bool defer_commits) const;
   void SetNeedsRedrawOnImpl(const gfx::Rect& damage_rect);
   void SetNeedsCommitOnImpl();
   void BeginMainFrameAbortedOnImpl(
       CommitEarlyOutReason reason,
       base::TimeTicks main_thread_start_time,
       std::vector<std::unique_ptr<SwapPromise>> swap_promises);
@@ skipping 92 matching lines @@
 
   std::unique_ptr<LayerTreeHostImpl> layer_tree_host_impl_;
 
   // Use accessors instead of this variable directly.
   BlockedMainCommitOnly main_thread_blocked_commit_vars_unsafe_;
   BlockedMainCommitOnly& blocked_main_commit();
 
   // 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);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_PROXY_IMPL_H_