NOT FOR LANDING Implement WebMediaSession

content/browser/media/android/media_session.h

 // Copyright 2015 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_BROWSER_MEDIA_ANDROID_MEDIA_SESSION_H_
 #define CONTENT_BROWSER_MEDIA_ANDROID_MEDIA_SESSION_H_
 
 #include <jni.h>
 #include <stddef.h>
 
@@ skipping 29 matching lines @@
     Content,
     Transient
   };
 
   static bool RegisterMediaSession(JNIEnv* env);
 
   // Returns the MediaSession associated to this WebContents. Creates one if
   // none is currently available.
   static MediaSession* Get(WebContents* web_contents);
 
+  // Returns a newly created standalone media session.
+  static MediaSession* Create(WebContents* web_contents, int session_id);
+
   ~MediaSession() override;
 
+  bool Activate();
+  void Deactivate();
+  int session_id() const { return session_id_; }
+
   // Adds the given player to the current media session. Returns whether the
   // player was successfully added. If it returns false, AddPlayer() should be
   // called again later.
   bool AddPlayer(MediaSessionObserver* observer, int player_id, Type type);
 
   // Removes the given player from the current media session. Abandons audio
   // focus if that was the last player in the session.
   void RemovePlayer(MediaSessionObserver* observer, int player_id);
 
   // Removes all the players associated with |observer|. Abandons audio focus if
@@ skipping 71 matching lines @@
     // Hash operator for base::hash_map<>.
     struct Hash {
       size_t operator()(const PlayerIdentifier& player_identifier) const;
     };
 
     MediaSessionObserver* observer;
     int player_id;
   };
   using PlayersMap = base::hash_set<PlayerIdentifier, PlayerIdentifier::Hash>;
 
-  explicit MediaSession(WebContents* web_contents);
+  MediaSession(WebContents* web_contents, int session_id = 0);
 
   // Setup the JNI.
   void Initialize();
 
   void OnSuspendInternal(SuspendType type, State new_state);
   void OnResumeInternal(SuspendType type);
 
   // Requests audio focus to Android using |j_media_session_|.
   // Returns whether the request was granted. If |j_media_session_| is null, it
   // will always return true.
   bool RequestSystemAudioFocus(Type type);
 
   // To be called after a call to AbandonAudioFocus() in order to call the Java
   // MediaSession if the audio focus really need to be abandoned.
   void AbandonSystemAudioFocusIfNeeded();
 
   // Notifies WebContents about the state change of the media session.
   void UpdateWebContents();
 
   // Internal method that should be used instead of setting audio_focus_state_.
   // It sets audio_focus_state_ and notifies observers about the state change.
   void SetAudioFocusState(State audio_focus_state);
 
   base::android::ScopedJavaGlobalRef<jobject> j_media_session_;
   PlayersMap players_;
 
   State audio_focus_state_;
   SuspendType suspend_type_;
   Type audio_focus_type_;
+  int session_id_;
 
   MediaSessionUmaHelper uma_helper_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaSession);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_ANDROID_MEDIA_SESSION_H_