Mac Overlays: Add GPU back-pressure

ui/gl/scoped_api.cc

Index: ui/gl/scoped_api.cc
diff --git a/ui/gl/scoped_api.cc b/ui/gl/scoped_api.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f43f692ac0f7a084f37ff4751a29b999552e8f75
--- /dev/null
+++ b/ui/gl/scoped_api.cc
@@ -0,0 +1,20 @@
+// 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/gl/scoped_api.h"
+
+#include "ui/gl/gl_gl_api_implementation.h"
+
+namespace gfx {
+
+ScopedSetGLToRealGLApi::ScopedSetGLToRealGLApi()
+    : old_gl_api_(GetCurrentGLApi()) {
+  SetGLToRealGLApi();
+}
+
+ScopedSetGLToRealGLApi::~ScopedSetGLToRealGLApi() {
+  SetGLApi(old_gl_api_);
+}
+
+}  // namespace gfx