Unified OutputSurface::SwapBuffers.

ui/compositor/compositor.h

Index: ui/compositor/compositor.h
diff --git a/ui/compositor/compositor.h b/ui/compositor/compositor.h
index 8e59b7e57476ba2b4f0d9df79138e6fa9691d69c..908dd662a675bdab90f5ced3eb50ae01d9224b99 100644
--- a/ui/compositor/compositor.h
+++ b/ui/compositor/compositor.h
@@ -262,6 +262,9 @@ class COMPOSITOR_EXPORT DrawWaiterForTest : public ui::CompositorObserver {
   // not to draw.
   static void Wait(Compositor* compositor);
 
+  // Waits for a commit instead of a draw.
+  static void WaitForCommit(Compositor* compositor);
+
  private:
   DrawWaiterForTest();
   virtual ~DrawWaiterForTest();
@@ -281,6 +284,8 @@ class COMPOSITOR_EXPORT DrawWaiterForTest : public ui::CompositorObserver {
 
   scoped_ptr<base::RunLoop> wait_run_loop_;
 
+  bool wait_for_commit_;
+
   DISALLOW_COPY_AND_ASSIGN(DrawWaiterForTest);
 };