Media: Add MEDIALOG_CREATED event

media/base/media_log_event.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 MEDIA_BASE_MEDIA_LOG_EVENT_H_
 #define MEDIA_BASE_MEDIA_LOG_EVENT_H_
 
 #include <stdint.h>
 #include <memory>
 
@@ skipping 12 matching lines @@
   MediaLogEvent& operator=(const MediaLogEvent& event) {
     id = event.id;
     type = event.type;
     std::unique_ptr<base::DictionaryValue> event_copy(event.params.DeepCopy());
     params.Swap(event_copy.get());
     time = event.time;
     return *this;
   }
 
   enum Type {
+    // A MediaLog is being created.
+    // params: none.
+    //
+    // This event allows the browser service to discard state but still
+    // determine which events belong to new players. It must be logged exactly
+    // once, as the first event in a MediaLog.
+    //
+    // Note: RenderMediaLog sends this event automatically; future
+    // implementations of MediaLog should do so as well.
+    MEDIALOG_CREATED,
+
     // A WebMediaPlayer is being created or destroyed.
     // params: none.
     WEBMEDIAPLAYER_CREATED,
     WEBMEDIAPLAYER_DESTROYED,
 
     // A media player is loading a resource.
     // params: "url": <URL of the resource>.
     LOAD,
 
     // A media player has started seeking.
@@ skipping 60 matching lines @@
 
   int32_t id;
   Type type;
   base::DictionaryValue params;
   base::TimeTicks time;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_MEDIA_LOG_EVENT_H_