Add tracing AutoOpenCloseEvent.

base/trace_event/video_playback_pae.h

+// Copyright 2016 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 BASE_TRACE_EVENT_VIDEO_PERSISTENT_ASYNC_H_
+#define BASE_TRACE_EVENT_VIDEO_PERSISTENT_ASYNC_H_
+
+#include "base/macros.h"
+#include "base/time/time.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/persistent_async_event.h"
+#include "base/trace_event/trace_event.h"

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

Is this include still needed?

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

Removed

+
+namespace base {
+
+namespace trace_event {
+
+// Class that provides a persistent async event for video playback.
+
+class BASE_EXPORT VideoPlaybackPersistentAsyncEvent
+    : public PersistentAsyncEvent {
+ public:
+  VideoPlaybackPersistentAsyncEvent();
+  ~VideoPlaybackPersistentAsyncEvent() override;
+
+ protected:
+  void RecordStartEvent() override;
+  void RecordStartEventWithTimestamp(int64_t timestamp) override;
+  void RecordStopEvent() override;
+};
+
+}  // namespace trace_event
+}  // namespace base
+
+#endif  // BASE_TRACE_EVENT_VIDEO_PERSISTENT_ASYNC_H_