cc: Allow the main thread to cancel commits

cc/test/layer_tree_test.cc

 // 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.
 
 #include "cc/test/layer_tree_test.h"
 
 #include "base/command_line.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_registrar.h"
 #include "cc/animation/layer_animation_controller.h"
@@ skipping 215 matching lines @@
 
 // Implementation of LayerTreeHost callback interface.
 class LayerTreeHostClientForTesting : public LayerTreeHostClient {
  public:
   static scoped_ptr<LayerTreeHostClientForTesting> Create(
       TestHooks* test_hooks) {
     return make_scoped_ptr(new LayerTreeHostClientForTesting(test_hooks));
   }
   virtual ~LayerTreeHostClientForTesting() {}
 
-  virtual void WillBeginFrame() OVERRIDE {}
+  virtual void WillBeginFrame() OVERRIDE {
+    test_hooks_->WillBeginFrame();
+  }
 
   virtual void DidBeginFrame() OVERRIDE {}
 
   virtual void Animate(double monotonic_time) OVERRIDE {
     test_hooks_->Animate(base::TimeTicks::FromInternalValue(
         monotonic_time * base::Time::kMicrosecondsPerSecond));
   }
 
   virtual void Layout() OVERRIDE {
     test_hooks_->Layout();
   }
 
   virtual void ApplyScrollAndScale(gfx::Vector2d scroll_delta,
                                    float scale) OVERRIDE {
     test_hooks_->ApplyScrollAndScale(scroll_delta, scale);
   }
 
   virtual scoped_ptr<OutputSurface> CreateOutputSurface() OVERRIDE {
     return test_hooks_->CreateOutputSurface();
   }
 
   virtual void DidInitializeOutputSurface(bool succeeded) OVERRIDE {
     test_hooks_->DidInitializeOutputSurface(succeeded);
   }
 
   virtual void DidFailToInitializeOutputSurface() OVERRIDE {
     test_hooks_->DidFailToInitializeOutputSurface();
   }
 
-  virtual void WillCommit() OVERRIDE {}
+  virtual void WillCommit() OVERRIDE {
+    test_hooks_->WillCommit();
+  }
 
   virtual void DidCommit() OVERRIDE {
     test_hooks_->DidCommit();
   }
 
   virtual void DidCommitAndDrawFrame() OVERRIDE {
     test_hooks_->DidCommitAndDrawFrame();
   }
 
   virtual void DidCompleteSwapBuffers() OVERRIDE {
@@ skipping 348 matching lines @@
 
 scoped_refptr<cc::ContextProvider> LayerTreeTest::
     OffscreenContextProviderForCompositorThread() {
   if (!compositor_thread_contexts_.get() ||
       compositor_thread_contexts_->DestroyedOnMainThread())
     compositor_thread_contexts_ = FakeContextProvider::Create();
   return compositor_thread_contexts_;
 }
 
 }  // namespace cc