Fix race conditions in window snapshot code.

cc/test/layer_tree_test.h

 // Copyright 2011 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_TEST_LAYER_TREE_TEST_H_
 #define CC_TEST_LAYER_TREE_TEST_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/threading/thread.h"
 #include "cc/animation/animation_delegate.h"
@@ skipping 100 matching lines @@
   void EndTestAfterDelay(int delay_milliseconds);
 
   void PostAddAnimationToMainThread(Layer* layer_to_receive_animation);
   void PostAddInstantAnimationToMainThread(Layer* layer_to_receive_animation);
   void PostSetNeedsCommitToMainThread();
   void PostReadbackToMainThread();
   void PostAcquireLayerTextures();
   void PostSetNeedsRedrawToMainThread();
   void PostSetNeedsRedrawRectToMainThread(gfx::Rect damage_rect);
   void PostSetVisibleToMainThread(bool visible);
+  void PostSetNextCommitForcesRedrawToMainThread();
 
   void DoBeginTest();
   void Timeout();
 
  protected:
   LayerTreeTest();
 
   virtual void InitializeSettings(LayerTreeSettings* settings) {}
 
   virtual void ScheduleComposite() OVERRIDE;
 
   void RealEndTest();
 
   virtual void DispatchAddInstantAnimation(Layer* layer_to_receive_animation);
   virtual void DispatchAddAnimation(Layer* layer_to_receive_animation);
   void DispatchSetNeedsCommit();
   void DispatchReadback();
   void DispatchAcquireLayerTextures();
   void DispatchSetNeedsRedraw();
   void DispatchSetNeedsRedrawRect(gfx::Rect damage_rect);
   void DispatchSetVisible(bool visible);
+  void DispatchSetNextCommitForcesRedraw();
   void DispatchComposite();
   void DispatchDidAddAnimation();
 
   virtual void RunTest(bool threaded,
                        bool delegating_renderer,
                        bool impl_side_painting);
 
   bool HasImplThread() { return proxy() ? proxy()->HasImplThread() : false; }
   base::SingleThreadTaskRunner* ImplThreadTaskRunner() {
     DCHECK(proxy());
@@ skipping 93 matching lines @@
 
 #define SINGLE_AND_MULTI_THREAD_DELEGATING_RENDERER_TEST_F(TEST_FIXTURE_NAME) \
   SINGLE_THREAD_DELEGATING_RENDERER_TEST_F(TEST_FIXTURE_NAME);                \
   MULTI_THREAD_DELEGATING_RENDERER_TEST_F(TEST_FIXTURE_NAME)
 
 #define SINGLE_AND_MULTI_THREAD_TEST_F(TEST_FIXTURE_NAME) \
   SINGLE_AND_MULTI_THREAD_DIRECT_RENDERER_TEST_F(TEST_FIXTURE_NAME);    \
   SINGLE_AND_MULTI_THREAD_DELEGATING_RENDERER_TEST_F(TEST_FIXTURE_NAME)
 
 #endif  // CC_TEST_LAYER_TREE_TEST_H_