Improve GL bindings for Ganesh surfaces.

mojo/skia/ganesh_context.h

 // Copyright 2014 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 MOJO_SKIA_GANESH_CONTEXT_H_
 #define MOJO_SKIA_GANESH_CONTEXT_H_
 
 #include "base/basictypes.h"
-#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "mojo/gpu/gl_context.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/gpu/GrContext.h"
 
 namespace gpu {
 namespace gles2 {
 class GLES2Interface;
 }
 }
 
@@ skipping 25 matching lines @@
 
   base::WeakPtr<GLContext> gl_context_;
   skia::RefPtr<GrContext> context_;
 
   DISALLOW_COPY_AND_ASSIGN(GaneshContext);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_SKIA_GANESH_CONTEXT_H_