compositor: Add rAF-like functionality for the UI.

ui/compositor/animation_frame_task.cc

+// Copyright 2014 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/compositor/animation_frame_task.h"
+
+#include "base/callback.h"
+
+namespace ui {
+
+ScopedAnimationFrameTask::ScopedAnimationFrameTask(
+    AnimationFrameTask* task,
+    const base::Closure& destroy_callback)
+    : task_(task), destroy_callback_(destroy_callback) {
+}
+
+ScopedAnimationFrameTask::~ScopedAnimationFrameTask() {
+  destroy_callback_.Run();
+}
+
+}  // namespace ui