(not for commit) Create 2nd ContextProvider for Ganesh rasterization.

content/renderer/gpu/compositor_output_surface.h

Index: content/renderer/gpu/compositor_output_surface.h
diff --git a/content/renderer/gpu/compositor_output_surface.h b/content/renderer/gpu/compositor_output_surface.h
index a8e1764e64833d415ff8c6c7d389a0a6745f143a..76af1f284743999ac78ac6b60ab913f1465f3291 100644
--- a/content/renderer/gpu/compositor_output_surface.h
+++ b/content/renderer/gpu/compositor_output_surface.h
@@ -43,6 +43,8 @@ class CompositorOutputSurface
       int32 routing_id,
       uint32 output_surface_id,
       const scoped_refptr<ContextProviderCommandBuffer>& context_provider,
+      const scoped_refptr<ContextProviderCommandBuffer>&
+          worker_context_provider,
       scoped_ptr<cc::SoftwareOutputDevice> software,
       scoped_refptr<FrameSwapMessageQueue> swap_frame_message_queue,
       bool use_swap_compositor_frame_message);
@@ -97,6 +99,7 @@ class CompositorOutputSurface
   scoped_refptr<CompositorForwardingMessageFilter> output_surface_filter_;
   CompositorForwardingMessageFilter::Handler output_surface_filter_handler_;
   scoped_refptr<CompositorOutputSurfaceProxy> output_surface_proxy_;
+  scoped_refptr<cc::ContextProvider> worker_context_provider_;
   scoped_refptr<IPC::SyncMessageFilter> message_sender_;
   scoped_refptr<FrameSwapMessageQueue> frame_swap_message_queue_;
   int routing_id_;