Letting Flash join MediaSession (stack implementaion)

content/browser/media/session/media_session.cc

Index: content/browser/media/session/media_session.cc
diff --git a/content/browser/media/session/media_session.cc b/content/browser/media/session/media_session.cc
index f76c5662bfe8b284464983690958753fba80458b..1c3af1ba6666a99a54f995b758bb918632e30029 100644
--- a/content/browser/media/session/media_session.cc
+++ b/content/browser/media/session/media_session.cc
@@ -71,6 +71,9 @@ void MediaSession::SetMetadata(const base::Optional<MediaMetadata>& metadata) {
 bool MediaSession::AddPlayer(MediaSessionObserver* observer,
                              int player_id,
                              media::MediaContentType media_content_type) {
+  if (media_content_type == media::MediaContentType::Pepper)
+    return AddPepperPlayer(observer, player_id);
+
   observer->OnSetVolumeMultiplier(player_id, GetVolumeMultiplier());
 
   // Determine the audio focus type required for playing the new player.
@@ -122,17 +125,28 @@ void MediaSession::RemovePlayer(MediaSessionObserver* observer,
   if (it != players_.end())
     players_.erase(it);
 
+  it = pepper_players_.find(PlayerIdentifier(observer, player_id));
+  if (it != pepper_players_.end())
+    pepper_players_.erase(it);
+
   AbandonSystemAudioFocusIfNeeded();
 }
 
 void MediaSession::RemovePlayers(MediaSessionObserver* observer) {
-  for (auto it = players_.begin(); it != players_.end();) {
+  for (auto it = players_.begin(); it != players_.end(); ) {
     if (it->observer == observer)
       players_.erase(it++);
     else
       ++it;
   }
 
+  for (auto it = pepper_players_.begin(); it != pepper_players_.end(); ) {
+    if (it->observer == observer)
+      pepper_players_.erase(it++);
+    else
+      ++it;
+  }
+
   AbandonSystemAudioFocusIfNeeded();
 }
 
@@ -190,8 +204,8 @@ void MediaSession::Suspend(SuspendType suspend_type) {
 
 void MediaSession::Stop(SuspendType suspend_type) {
   DCHECK(audio_focus_state_ != State::INACTIVE);
-
   DCHECK(suspend_type != SuspendType::CONTENT);
+  DCHECK(!HasPepper());
 
   // TODO(mlamouri): merge the logic between UI and SYSTEM.
   if (suspend_type == SuspendType::SYSTEM) {
@@ -204,6 +218,7 @@ void MediaSession::Stop(SuspendType suspend_type) {
 
   DCHECK(audio_focus_state_ == State::SUSPENDED);
   players_.clear();
+
   AbandonSystemAudioFocusIfNeeded();
 }
 
@@ -250,6 +265,10 @@ bool MediaSession::IsControllable() const {
          audio_focus_type_ == AudioFocusManager::AudioFocusType::Gain;
 }
 
+bool MediaSession::HasPepper() const {
+  return !pepper_players_.empty();
+}
+
 std::unique_ptr<base::CallbackList<void(MediaSession::State)>::Subscription>
 MediaSession::RegisterMediaSessionStateChangedCallbackForTest(
     const StateChangedCallback& cb) {
@@ -323,6 +342,9 @@ void MediaSession::OnSuspendInternal(SuspendType suspend_type,
       it.observer->OnSuspend(it.player_id);
   }
 
+  for (const auto& it : pepper_players_)
+    it.observer->OnSetVolumeMultiplier(it.player_id, kDuckingVolumeMultiplier);
+
   UpdateWebContents();
 }
 
@@ -335,6 +357,10 @@ void MediaSession::OnResumeInternal(SuspendType suspend_type) {
   for (const auto& it : players_)
     it.observer->OnResume(it.player_id);
 
+  for (const auto& it : pepper_players_)
+    it.observer->OnSetVolumeMultiplier(
+        it.player_id, GetVolumeMultiplier());
+
   UpdateWebContents();
 }
 
@@ -357,7 +383,8 @@ bool MediaSession::RequestSystemAudioFocus(
 }
 
 void MediaSession::AbandonSystemAudioFocusIfNeeded() {
-  if (audio_focus_state_ == State::INACTIVE || !players_.empty())
+  if (audio_focus_state_ == State::INACTIVE || !players_.empty() ||
+      !pepper_players_.empty())
     return;
 
   delegate_->AbandonAudioFocus();
@@ -389,4 +416,19 @@ void MediaSession::SetAudioFocusState(State audio_focus_state) {
   }
 }
 
+bool MediaSession::AddPepperPlayer(MediaSessionObserver* observer,
+                                   int player_id) {
+  AudioFocusManager::AudioFocusType focus_type =
+      AudioFocusManager::AudioFocusType::Gain;
+  State audio_focus_state =
+      RequestSystemAudioFocus(focus_type) ? State::ACTIVE : State::INACTIVE;
+  SetAudioFocusState(audio_focus_state);
+  audio_focus_type_ = focus_type;
+  pepper_players_.insert(PlayerIdentifier(observer, player_id));
+
+  observer->OnSetVolumeMultiplier(player_id, GetVolumeMultiplier());
+
+  return true;
+}
+
 }  // namespace content