Letting Flash join MediaSession (stack implementaion)

content/browser/media/session/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_SESSION_MEDIA_SESSION_H_
 #define CONTENT_BROWSER_MEDIA_SESSION_MEDIA_SESSION_H_
 
 #include <stddef.h>
 
 #include "base/callback_list.h"
@@ skipping 85 matching lines @@
   CONTENT_EXPORT void Resume(SuspendType suspend_type);
 
   // Suspend the media session.
   // |type| represents the origin of the request.
   CONTENT_EXPORT void Suspend(SuspendType suspend_type);
 
   // Stop the media session.
   // |type| represents the origin of the request.
   CONTENT_EXPORT void Stop(SuspendType suspend_type);
 
-  // Change the volume multiplier of the session to |volume_multiplier|.
-  CONTENT_EXPORT void SetVolumeMultiplier(double volume_multiplier);
+  CONTENT_EXPORT void Duck();
+  CONTENT_EXPORT void Unduck();
+
+  CONTENT_EXPORT bool IsDucking() { return is_ducking_; }
 
   // Returns if the session can be controlled by Resume() and Suspend calls
   // above.
   CONTENT_EXPORT bool IsControllable() const;
 
   // Returns if the session is currently active.
   CONTENT_EXPORT bool IsActive() const;
 
   // Returns if the session is currently suspended.
   // TODO(mlamouri): IsSuspended() below checks if the state is not ACTIVE
   // instead of checking if the state is SUSPENDED. In order to not have to
   // change all the callers and make the current refactoring ridiculously huge,
   // this method is introduced temporarily and will be removed later.
   bool IsReallySuspended() const;
 
   // Returns if the session is currently suspended or inactive.
   CONTENT_EXPORT bool IsSuspended() const;
 
+  void SetOnTop(bool is_on_top);
+
  private:
   friend class content::WebContentsUserData<MediaSession>;
   friend class ::MediaSessionBrowserTest;
   friend class content::MediaSessionVisibilityBrowserTest;
   friend class content::AudioFocusManagerTest;
   friend class content::MediaSessionStateObserver;
 
   CONTENT_EXPORT void SetDelegateForTests(
       std::unique_ptr<MediaSessionDelegate> delegate);
   CONTENT_EXPORT bool IsActiveForTest() const;
@@ skipping 49 matching lines @@
 
   // 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);
 
   // Registers a MediaSession state change callback.
   CONTENT_EXPORT std::unique_ptr<base::CallbackList<void(State)>::Subscription>
   RegisterMediaSessionStateChangedCallbackForTest(
       const StateChangedCallback& cb);
 
+  CONTENT_EXPORT bool AddPepperPlayer(MediaSessionObserver* observer,
+                                      int player_id);
+
+  double GetVolumeMultiplier() const;
+  double GetPepperVolumeMultiplier() const;
+
   std::unique_ptr<MediaSessionDelegate> delegate_;
   PlayersMap players_;
+  PlayersMap pepper_players_;
 
   State audio_focus_state_;
   SuspendType suspend_type_;
   AudioFocusManager::AudioFocusType audio_focus_type_;
 
   MediaSessionUmaHelper uma_helper_;
 
-  // The volume multiplier of this session. All players in this session should
-  // multiply their volume with this multiplier to get the effective volume.
-  double volume_multiplier_;
+  // Whether this session is ducked, which is used to compute the volume
+  // multiplier of this session. All players in this session should multiply
+  // their volume with this multiplier to get the effective volume.
+  bool is_ducking_;
+
+  bool is_on_top_;
 
   MediaMetadata metadata_;
   base::CallbackList<void(State)> media_session_state_listeners_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaSession);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_SESSION_MEDIA_SESSION_H_