cc: Emulate BeginFrame in OutputSurfaces that don't support it natively

cc/test/fake_output_surface.h

Index: cc/test/fake_output_surface.h
diff --git a/cc/test/fake_output_surface.h b/cc/test/fake_output_surface.h
index d54ffd3cdaf41c16a2f3ba1372b99198f20216c5..7bc1a4f4c75bc0881f9464e60ab2442aa7f1d1c4 100644
--- a/cc/test/fake_output_surface.h
+++ b/cc/test/fake_output_surface.h
@@ -74,7 +74,6 @@ class FakeOutputSurface : public OutputSurface {
   bool needs_begin_frame() const {
     return needs_begin_frame_;
   }
-  void BeginFrame(base::TimeTicks frame_time);
 
   void set_forced_draw_to_software_device(bool forced) {
     forced_draw_to_software_device_ = forced;
@@ -95,10 +94,13 @@ class FakeOutputSurface : public OutputSurface {
       scoped_ptr<SoftwareOutputDevice> software_device,
       bool delegated_rendering);
 
+  void OnBeginFrame();
+
   CompositorFrame last_sent_frame_;
   size_t num_sent_frames_;
   bool needs_begin_frame_;
   bool forced_draw_to_software_device_;
+  base::WeakPtrFactory<FakeOutputSurface> fake_weak_ptr_factory_;
 };
 
 static inline scoped_ptr<cc::OutputSurface> CreateFakeOutputSurface() {