Remove GPU relinquish resources infrastructure and stop GPU process.

ui/ozone/platform/cast/gpu_platform_support_cast.cc

Index: ui/ozone/platform/cast/gpu_platform_support_cast.cc
diff --git a/ui/ozone/platform/cast/gpu_platform_support_cast.cc b/ui/ozone/platform/cast/gpu_platform_support_cast.cc
index 5dfaf4a6f4e553e08f57dd2275446def739d5b5e..d434f02de55b50d0fb4db4b1415ed116318966d6 100644
--- a/ui/ozone/platform/cast/gpu_platform_support_cast.cc
+++ b/ui/ozone/platform/cast/gpu_platform_support_cast.cc
@@ -12,11 +12,6 @@ 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;
 }