Infrastructure for temportarily relinquishing GPU resources.

ui/ozone/public/gpu_platform_support.cc

Index: ui/ozone/public/gpu_platform_support.cc
diff --git a/ui/ozone/public/gpu_platform_support.cc b/ui/ozone/public/gpu_platform_support.cc
index 4b7f52758495c7b5655da1209a79b63a85c01164..a2457cdcdb5446147eb4ffcf67a3fefde1c46270 100644
--- a/ui/ozone/public/gpu_platform_support.cc
+++ b/ui/ozone/public/gpu_platform_support.cc
@@ -17,8 +17,14 @@ class StubGpuPlatformSupport : public GpuPlatformSupport {
   // GpuPlatformSupport:
   void OnChannelEstablished(IPC::Sender* sender) override {}
   bool OnMessageReceived(const IPC::Message&) override { return false; }
+  void RelinquishGpuResources(const base::Closure& callback) override;
 };
 
+void StubGpuPlatformSupport::RelinquishGpuResources(
+    const base::Closure& callback) {
+  callback.Run();
+}
+
 }  // namespace
 
 GpuPlatformSupport::GpuPlatformSupport() {