Add tracing AutoOpenCloseEvent.

media/blink/video_frame_compositor.h

 // 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.
 
 #ifndef MEDIA_BLINK_VIDEO_FRAME_COMPOSITOR_H_
 #define MEDIA_BLINK_VIDEO_FRAME_COMPOSITOR_H_
 
 #include <utility>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
 #include "base/time/tick_clock.h"
 #include "base/timer/timer.h"
 #include "cc/layers/video_frame_provider.h"
 #include "media/base/video_renderer_sink.h"
 #include "media/blink/media_blink_export.h"
 #include "ui/gfx/geometry/size.h"
 
+namespace base {
+namespace trace_event {
+class AutoOpenCloseEvent;
+}
+}
+
 namespace media {
 class VideoFrame;
 
 // VideoFrameCompositor acts as a bridge between the media and cc layers for
 // rendering video frames. I.e. a media::VideoRenderer will talk to this class
 // from the media side, while a cc::VideoFrameProvider::Client will talk to it
 // from the cc side.
 //
 // This class is responsible for requesting new frames from a video renderer in
 // response to requests from the VFP::Client. Since the VFP::Client may stop
@@ skipping 121 matching lines @@
   base::TimeTicks last_background_render_;
 
   // These values are set on the compositor thread, but also read on the media
   // thread when the VFC is stopped.
   scoped_refptr<VideoFrame> current_frame_;
 
   // These values are updated and read from the media and compositor threads.
   base::Lock callback_lock_;
   VideoRendererSink::RenderCallback* callback_;
 
+  // AutoOpenCloseEvent for begin/end events.
+  std::unique_ptr<base::trace_event::AutoOpenCloseEvent> auto_open_close_;
+
   DISALLOW_COPY_AND_ASSIGN(VideoFrameCompositor);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BLINK_VIDEO_FRAME_COMPOSITOR_H_