Use ContextProvider subclass to provide WGC3D pointers

content/renderer/android/synchronous_compositor_factory.h

Index: content/renderer/android/synchronous_compositor_factory.h
diff --git a/content/renderer/android/synchronous_compositor_factory.h b/content/renderer/android/synchronous_compositor_factory.h
index 77c0500426626ed65f50539f53884e31b794893c..18a907e614e71accb6c3820f3260b296af2d8db7 100644
--- a/content/renderer/android/synchronous_compositor_factory.h
+++ b/content/renderer/android/synchronous_compositor_factory.h
@@ -17,6 +17,12 @@ class ContextProvider;
 class OutputSurface;
 }
 
+namespace webkit {
+namespace gpu {
+class ContextProviderWebContext;
+}
+}
+
 namespace content {
 
 class InputHandlerManagerClient;
@@ -41,7 +47,7 @@ class SynchronousCompositorFactory {
   // The factory maintains ownership of the returned interface.
   virtual InputHandlerManagerClient* GetInputHandlerManagerClient() = 0;
 
-  virtual scoped_refptr<cc::ContextProvider>
+  virtual scoped_refptr<webkit::gpu::ContextProviderWebContext>
       GetOffscreenContextProviderForMainThread() = 0;
   virtual scoped_refptr<cc::ContextProvider>
       GetOffscreenContextProviderForCompositorThread() = 0;