GPU process clients can perform a "shallow" finish.

cc/output/software_renderer.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_SOFTWARE_RENDERER_H_
 #define CC_OUTPUT_SOFTWARE_RENDERER_H_
 
 #include "base/basictypes.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/compositor_frame.h"
@@ skipping 16 matching lines @@
 
 class CC_EXPORT SoftwareRenderer : public DirectRenderer {
  public:
   static scoped_ptr<SoftwareRenderer> Create(
       RendererClient* client,
       OutputSurface* output_surface,
       ResourceProvider* resource_provider);
 
   virtual ~SoftwareRenderer();
   virtual const RendererCapabilities& Capabilities() const OVERRIDE;
-  virtual void Finish() OVERRIDE;
+  //virtual void Finish() OVERRIDE;
   virtual void SwapBuffers() OVERRIDE;
   virtual void GetFramebufferPixels(void* pixels, gfx::Rect rect) OVERRIDE;
   virtual void SetVisible(bool visible) OVERRIDE;
   virtual void SendManagedMemoryStats(
       size_t bytes_visible,
       size_t bytes_visible_and_nearby,
       size_t bytes_allocated) OVERRIDE  {}
   virtual void ReceiveSwapBuffersAck(
       const CompositorFrameAck& ack) OVERRIDE;
 
@@ skipping 55 matching lines @@
   scoped_ptr<ResourceProvider::ScopedWriteLockSoftware>
       current_framebuffer_lock_;
   scoped_ptr<SoftwareFrameData> current_frame_data_;
 
   DISALLOW_COPY_AND_ASSIGN(SoftwareRenderer);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_SOFTWARE_RENDERER_H_