Letting Flash join MediaSession (stack implementaion)

content/browser/media/session/media_session.h

Index: content/browser/media/session/media_session.h
diff --git a/content/browser/media/session/media_session.h b/content/browser/media/session/media_session.h
index 9d501fcfd8b7324f41eaf052962620b96e4c43fb..3f89cfec433a60bce46f24b332e5b47eb6a690f5 100644
--- a/content/browser/media/session/media_session.h
+++ b/content/browser/media/session/media_session.h
@@ -63,6 +63,8 @@ class MediaSession : public WebContentsObserver,
 
   ~MediaSession() override;
 
+  void WasShown() override;

[mlamouri (slow - plz ping), 2016/09/05 09:40:36]

To simplify understanding this, can you explain why you are doing this?

[Zhiqiang Zhang (Slow), 2016/09/05 09:54:21]

Oh, it seems like the code when I was doing experimental which gives audio focus
to a tab when the tab is brought to front.

Will remove this.

+
   void SetMetadata(const MediaMetadata& metadata);
   const MediaMetadata& metadata() const { return metadata_; }
 
@@ -111,6 +113,8 @@ class MediaSession : public WebContentsObserver,
   // recovered.
   CONTENT_EXPORT void StopDucking();
 
+  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;
@@ -128,6 +132,8 @@ class MediaSession : public WebContentsObserver,
   // Returns if the session is currently suspended or inactive.
   CONTENT_EXPORT bool IsSuspended() const;
 
+  void SetOnTop(bool is_on_top);

[mlamouri (slow - plz ping), 2016/09/05 09:40:36]

ditto, what's `SetOnTop` for?

[Zhiqiang Zhang (Slow), 2016/09/05 09:54:21]

I discussed this with Anton, and the method is actually something like
"DuckPepper(bool is_duck)"

+
  private:
   friend class content::WebContentsUserData<MediaSession>;
   friend class ::MediaSessionBrowserTest;
@@ -198,14 +204,19 @@ class MediaSession : public WebContentsObserver,
   // Get the volume multiplier, which depends on whether the media session is
   // ducking.
   double GetVolumeMultiplier() const;
+  double GetPepperVolumeMultiplier() const;
 
   // 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);
+
   std::unique_ptr<MediaSessionDelegate> delegate_;
   PlayersMap players_;
+  PlayersMap pepper_players_;
 
   State audio_focus_state_;
   SuspendType suspend_type_;
@@ -217,6 +228,7 @@ class MediaSession : public WebContentsObserver,
   // is set to |true| after StartDucking(), and will be set to |false| after
   // StopDucking().
   bool is_ducking_;
+  bool is_on_top_;
 
   MediaMetadata metadata_;
   base::CallbackList<void(State)> media_session_state_listeners_;