Limit outstanding surface draw swaps to max_frames_pending.

cc/surfaces/display.h

Index: cc/surfaces/display.h
diff --git a/cc/surfaces/display.h b/cc/surfaces/display.h
index 07e87adc1c9b8879dc0d7065fc7a995ba1d75056..b4782364ad00c86c706981b2a1fb4101be511460 100644
--- a/cc/surfaces/display.h
+++ b/cc/surfaces/display.h
@@ -47,6 +47,7 @@ class CC_SURFACES_EXPORT Display : public OutputSurfaceClient,
   bool Draw();
 
   SurfaceId CurrentSurfaceId();
+  int GetMaxFramesPending();
 
   // OutputSurfaceClient implementation.
   virtual void DeferredInitialize() OVERRIDE {}
@@ -55,8 +56,8 @@ class CC_SURFACES_EXPORT Display : public OutputSurfaceClient,
                                      base::TimeDelta interval) OVERRIDE {}
   virtual void SetNeedsRedrawRect(const gfx::Rect& damage_rect) OVERRIDE {}
   virtual void BeginFrame(const BeginFrameArgs& args) OVERRIDE {}
-  virtual void DidSwapBuffers() OVERRIDE {}
-  virtual void DidSwapBuffersComplete() OVERRIDE {}
+  virtual void DidSwapBuffers() OVERRIDE;
+  virtual void DidSwapBuffersComplete() OVERRIDE;
   virtual void ReclaimResources(const CompositorFrameAck* ack) OVERRIDE {}
   virtual void DidLoseOutputSurface() OVERRIDE {}
   virtual void SetExternalDrawConstraints(