Add ShellDelegate, MediaDelegate and KeyboardUI stubs to mus ash

ash/gpu_support_stub.cc

Index: ash/gpu_support_stub.cc
diff --git a/ash/gpu_support_stub.cc b/ash/gpu_support_stub.cc
deleted file mode 100644
index 42f468d4725ff01bc8acb84f6c4e34cbf1524ec7..0000000000000000000000000000000000000000
--- a/ash/gpu_support_stub.cc
+++ /dev/null
@@ -1,22 +0,0 @@
-// 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.
-
-#include "ash/gpu_support_stub.h"
-
-namespace ash {
-
-GPUSupportStub::GPUSupportStub() {}
-
-GPUSupportStub::~GPUSupportStub() {}
-
-bool GPUSupportStub::IsPanelFittingDisabled() const {
-  return false;
-}
-
-void GPUSupportStub::DisableGpuWatchdog() {}
-
-void GPUSupportStub::GetGpuProcessHandles(
-    const GetGpuProcessHandlesCallback& callback) const {}
-
-}  // namespace ash