Add tracing AutoOpenCloseEvent.

media/blink/video_frame_compositor.cc

Index: media/blink/video_frame_compositor.cc
diff --git a/media/blink/video_frame_compositor.cc b/media/blink/video_frame_compositor.cc
index 544f7098701d481c2358c2493d2f59aae52d5256..227917ca27251ba0f671bac910954711c8227b54 100644
--- a/media/blink/video_frame_compositor.cc
+++ b/media/blink/video_frame_compositor.cc
@@ -8,6 +8,9 @@
 #include "base/message_loop/message_loop.h"
 #include "base/time/default_tick_clock.h"
 #include "base/trace_event/trace_event.h"
+#include "base/trace_event/trace_event_impl.h"

[benjhayden, 2016/08/30 04:17:24]

Is this include still needed?

[alexandermont, 2016/08/30 19:01:22]

Removed

+#include "base/trace_event/trace_log.h"

[benjhayden, 2016/08/30 04:17:24]

Is this include still needed?

[alexandermont, 2016/08/30 19:01:22]

Removed

+#include "base/trace_event/video_playback_pae.h"
 #include "media/base/video_frame.h"
 
 namespace media {
@@ -35,7 +38,9 @@ VideoFrameCompositor::VideoFrameCompositor(
       new_background_frame_(false),
       // Assume 60Hz before the first UpdateCurrentFrame() call.
       last_interval_(base::TimeDelta::FromSecondsD(1.0 / 60)),
-      callback_(nullptr) {
+      callback_(nullptr),
+      persistent_async_(
+          new base::trace_event::VideoPlaybackPersistentAsyncEvent()) {
   background_rendering_timer_.SetTaskRunner(compositor_task_runner_);
 }
 
@@ -105,8 +110,7 @@ bool VideoFrameCompositor::HasCurrentFrame() {
 }
 
 void VideoFrameCompositor::Start(RenderCallback* callback) {
-  TRACE_EVENT_ASYNC_BEGIN0("media,rail", "VideoPlayback",
-                           static_cast<const void*>(this));
+  persistent_async_->Start();
 
   // Called from the media thread, so acquire the callback under lock before
   // returning in case a Stop() call comes in before the PostTask is processed.
@@ -119,8 +123,7 @@ void VideoFrameCompositor::Start(RenderCallback* callback) {
 }
 
 void VideoFrameCompositor::Stop() {
-  TRACE_EVENT_ASYNC_END0("media,rail", "VideoPlayback",
-                         static_cast<const void*>(this));
+  persistent_async_->Stop();
 
   // Called from the media thread, so release the callback under lock before
   // returning to avoid a pending UpdateCurrentFrame() call occurring before