[Mojo] Remove dependency between mojo/public and gpu

mojo/examples/sample_app/sample_gles2_delegate.h

-// Copyright 2013 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_EXAMPLES_SAMPLE_APP_SAMPLE_GLES2_DELEGATE_H_
-#define MOJO_EXAMPLES_SAMPLE_APP_SAMPLE_GLES2_DELEGATE_H_
-
-#include "base/timer/timer.h"
-#include "mojo/examples/sample_app/spinning_cube.h"
-#include "mojo/public/bindings/gles2_client/gles2_client_impl.h"
-
-namespace mojo {
-namespace examples {
-
-class SampleGLES2Delegate : public GLES2Delegate {
- public:
-  SampleGLES2Delegate();
-  virtual ~SampleGLES2Delegate();
-
- private:
-  virtual void DidCreateContext(
-      GLES2ClientImpl* gl, uint32_t width, uint32_t height) MOJO_OVERRIDE;
-  virtual void ContextLost(GLES2ClientImpl* gl) MOJO_OVERRIDE;
-
-  void Draw();
-
-  base::Time last_time_;
-  base::RepeatingTimer<SampleGLES2Delegate> timer_;
-  SpinningCube cube_;
-  GLES2ClientImpl* gl_;
-};
-
-}  // namespace examples
-}  // namespace mojo
-
-#endif  // MOJO_EXAMPLES_SAMPLE_APP_SAMPLE_GLES2_DELEGATE_H_