Convert MediaLog from being ref counted to owned by WebMediaPlayer.

content/renderer/media/render_media_log.h

 // Copyright (c) 2012 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 CONTENT_RENDERER_MEDIA_RENDER_MEDIA_LOG_H_
 #define CONTENT_RENDERER_MEDIA_RENDER_MEDIA_LOG_H_
 
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/time/time.h"
 #include "content/common/content_export.h"
 #include "media/base/media_log.h"
 #include "url/gurl.h"
 
 namespace base {
 class TickClock;
 }
 
 namespace content {
 
 // RenderMediaLog is an implementation of MediaLog that forwards events to the
 // browser process, throttling as necessary.
 //
 // It also caches the last error events to support renderer-side reporting to
 // entities like HTMLMediaElement and devtools console.
 //
 // To minimize the number of events sent over the wire, only the latest event
 // added is sent for high frequency events (e.g., BUFFERED_EXTENTS_CHANGED).
 //
 // It must be constructed on the render thread.
 class CONTENT_EXPORT RenderMediaLog : public media::MediaLog {
  public:
   explicit RenderMediaLog(const GURL& security_origin);
+  ~RenderMediaLog() override;
 
   // MediaLog implementation.
   void AddEvent(std::unique_ptr<media::MediaLogEvent> event) override;
   std::string GetLastErrorMessage() override;
   void RecordRapporWithSecurityOrigin(const std::string& metric) override;
 
   // Will reset |last_ipc_send_time_| with the value of NowTicks().
   void SetTickClockForTesting(std::unique_ptr<base::TickClock> tick_clock);
   void SetTaskRunnerForTesting(
       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
 
  private:
-  ~RenderMediaLog() override;
-
   // Posted as a delayed task on |task_runner_| to throttle ipc message
   // frequency.
   void SendQueuedMediaEvents();
 
   // Security origin of the current frame.
   const GURL security_origin_;
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   // |lock_| protects access to all of the following member variables.  It
@@ skipping 11 matching lines @@
   // Limits the number of events we send over IPC to one.
   std::unique_ptr<media::MediaLogEvent> last_buffered_extents_changed_event_;
   std::unique_ptr<media::MediaLogEvent> last_duration_changed_event_;
 
   // Holds a copy of the most recent MEDIA_ERROR_LOG_ENTRY, if any.
   std::unique_ptr<media::MediaLogEvent> last_media_error_log_entry_;
 
   // Holds a copy of the most recent PIPELINE_ERROR, if any.
   std::unique_ptr<media::MediaLogEvent> last_pipeline_error_;
 
+  base::WeakPtr<RenderMediaLog> weak_this_;
+  base::WeakPtrFactory<RenderMediaLog> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderMediaLog);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_RENDER_MEDIA_LOG_H_