Tighter sync and faster ACK on SwapBuffers/PostSubBuffers

ui/compositor/layer_unittest.cc

 // Copyright (c) 2012 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 "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
@@ skipping 291 matching lines @@
   }
   virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE {
   }
 
   DISALLOW_COPY_AND_ASSIGN(NullLayerDelegate);
 };
 
 // Remembers if it has been notified.
 class TestCompositorObserver : public CompositorObserver {
  public:
-  TestCompositorObserver() : started_(false), ended_(false) {}
+  TestCompositorObserver() : started_(false), will_end_(false), ended_(false) {
+  }
 
-  bool notified() const { return started_ && ended_; }
+  bool notified() const { return started_ && will_end_ && ended_; }
 
   void Reset() {
     started_ = false;
+    will_end_ = false;
     ended_ = false;
   }
 
  private:
   virtual void OnCompositingStarted(Compositor* compositor) OVERRIDE {
     started_ = true;
   }
 
+  virtual void OnCompositingWillEnd(Compositor* compositor) OVERRIDE {
+    will_end_ = true;
+  }
+
   virtual void OnCompositingEnded(Compositor* compositor) OVERRIDE {
     ended_ = true;
   }
 
   bool started_;
+  bool will_end_;
   bool ended_;
 
   DISALLOW_COPY_AND_ASSIGN(TestCompositorObserver);
 };
 
 }  // namespace
 
 #if defined(OS_WIN)
 // These are disabled on windows as they don't run correctly on the buildbot.
 // Reenable once we move to the real compositor.
@@ skipping 914 matching lines @@
 
   // Resize layer.
   child->SetBounds(gfx::Rect(200, 200, 400, 400));
   child->SetVisible(true);
   EXPECT_TRUE(schedule_draw_invoked_);
   DrawTree(root.get());
   EXPECT_TRUE(delegate.painted());
 }
 
 } // namespace ui