cc: Make scheduling be driven by vsync for android webview.

cc/output/output_surface_client.h

 // Copyright 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.
 
 #ifndef CC_OUTPUT_OUTPUT_SURFACE_CLIENT_H_
 #define CC_OUTPUT_OUTPUT_SURFACE_CLIENT_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
@@ skipping 31 matching lines @@
       const gfx::Rect& clip,
       const gfx::Rect& viewport_rect_for_tile_priority,
       const gfx::Transform& transform_for_tile_priority,
       bool resourceless_software_draw) = 0;
   virtual void SetMemoryPolicy(const ManagedMemoryPolicy& policy) = 0;
   // If set, |callback| will be called subsequent to each new tree activation,
   // regardless of the compositor visibility or damage. |callback| must remain
   // valid for the lifetime of the OutputSurfaceClient or until unregisted --
   // use SetTreeActivationCallback(base::Closure()) to unregister it.
   virtual void SetTreeActivationCallback(const base::Closure& callback) = 0;
+  // This allows the output surface to ask it's client for a draw.
+  virtual void OnDraw() = 0;
 
  protected:
   virtual ~OutputSurfaceClient() {}
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_OUTPUT_SURFACE_CLIENT_H_