Remove GPU relinquish resources infrastructure and stop GPU process.

ui/ozone/platform/cast/gpu_platform_support_cast.cc

 // 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.
 
 #include "ui/ozone/platform/cast/gpu_platform_support_cast.h"
 
 #include "ui/ozone/platform/cast/surface_factory_cast.h"
 
 namespace ui {
 
 bool GpuPlatformSupportCast::OnMessageReceived(const IPC::Message& msg) {
   return false;
 }
 
-void GpuPlatformSupportCast::RelinquishGpuResources(
-    const base::Closure& callback) {
-  parent_->SetToRelinquishDisplay(callback);
-}
-
 IPC::MessageFilter* GpuPlatformSupportCast::GetMessageFilter() {
   return nullptr;
 }
 
 }  // namespace ui