Add ShellDelegate, MediaDelegate and KeyboardUI stubs to mus ash

ash/common/gpu_support_stub.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 ASH_GPU_SUPPORT_STUB_H_
-#define ASH_GPU_SUPPORT_STUB_H_
+#ifndef ASH_COMMON_GPU_SUPPORT_STUB_H_
+#define ASH_COMMON_GPU_SUPPORT_STUB_H_
 
 #include "ash/ash_export.h"
-#include "ash/gpu_support.h"
-#include "base/compiler_specific.h"
+#include "ash/common/gpu_support.h"
 #include "base/macros.h"
 
 namespace ash {
 
 // A GPUSupport object that does not depend on src/content.
 class ASH_EXPORT GPUSupportStub : public GPUSupport {
  public:
   GPUSupportStub();
   ~GPUSupportStub() override;
 
  private:
   // Overridden from GPUSupport:
   bool IsPanelFittingDisabled() const override;
   void DisableGpuWatchdog() override;
   void GetGpuProcessHandles(
       const GetGpuProcessHandlesCallback& callback) const override;
 
   DISALLOW_COPY_AND_ASSIGN(GPUSupportStub);
 };
 
 }  // namespace ash
 
-#endif  // ASH_GPU_SUPPORT_STUB_H_
+#endif  // ASH_COMMON_GPU_SUPPORT_STUB_H_