Remove GPU relinquish resources infrastructure and stop GPU process.

ui/ozone/platform/cast/gpu_platform_support_cast.h

 // Copyright 2015 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 UI_OZONE_PLATFORM_CAST_GPU_PLATFORM_SUPPORT_CAST_H_
 #define UI_OZONE_PLATFORM_CAST_GPU_PLATFORM_SUPPORT_CAST_H_
 
 #include "ui/ozone/public/gpu_platform_support.h"
 
 namespace ui {
 
 class SurfaceFactoryCast;
 
 // GpuPlatformSupport implementation for use with OzonePlatformCast.
 class GpuPlatformSupportCast : public GpuPlatformSupport {
  public:
   explicit GpuPlatformSupportCast(SurfaceFactoryCast* parent)
       : parent_(parent) {}
 
   // GpuPlatformSupport implementation:
   void OnChannelEstablished(IPC::Sender* sender) override {}
   bool OnMessageReceived(const IPC::Message& msg) override;
-  void RelinquishGpuResources(const base::Closure& callback) override;
   IPC::MessageFilter* GetMessageFilter() override;
 
  private:
   SurfaceFactoryCast* parent_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuPlatformSupportCast);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_CAST_GPU_PLATFORM_SUPPORT_CAST_H_