Mute audio for Spitzer playbacks that haven't received focus yet.

content/browser/media/android/media_session.cc

Index: content/browser/media/android/media_session.cc
diff --git a/content/browser/media/android/media_session.cc b/content/browser/media/android/media_session.cc
index e90daf417e6d72bb057719a550a15da5725e6b4f..9ee7456a1c650c75b97d0e7299e9791bcd531cf0 100644
--- a/content/browser/media/android/media_session.cc
+++ b/content/browser/media/android/media_session.cc
@@ -63,8 +63,6 @@ MediaSession::~MediaSession() {
 bool MediaSession::AddPlayer(MediaSessionObserver* observer,
                              int player_id,
                              Type type) {
-  observer->OnSetVolumeMultiplier(player_id, volume_multiplier_);
-
   // If the audio focus is already granted and is of type Content, there is
   // nothing to do. If it is granted of type Transient the requested type is
   // also transient, there is also nothing to do. Otherwise, the session needs
@@ -72,26 +70,28 @@ bool MediaSession::AddPlayer(MediaSessionObserver* observer,
   if (audio_focus_state_ == State::ACTIVE &&
       (audio_focus_type_ == Type::Content || audio_focus_type_ == type)) {
     players_.insert(PlayerIdentifier(observer, player_id));
-    return true;
-  }
+  } else {
+    State old_audio_focus_state = audio_focus_state_;
+    State audio_focus_state = RequestSystemAudioFocus(type) ? State::ACTIVE
+                                                            : State::INACTIVE;
+    SetAudioFocusState(audio_focus_state);
+    audio_focus_type_ = type;
 
-  State old_audio_focus_state = audio_focus_state_;
-  State audio_focus_state = RequestSystemAudioFocus(type) ? State::ACTIVE
-                                                          : State::INACTIVE;
-  SetAudioFocusState(audio_focus_state);
-  audio_focus_type_ = type;
-
-  if (audio_focus_state_ != State::ACTIVE)
-    return false;
+    if (audio_focus_state_ != State::ACTIVE)
+      return false;
 
-  // The session should be reset if a player is starting while all players are
-  // suspended.
-  if (old_audio_focus_state != State::ACTIVE)
-    players_.clear();
+    // The session should be reset if a player is starting while all players are
+    // suspended.
+    if (old_audio_focus_state != State::ACTIVE)
+      players_.clear();
 
-  players_.insert(PlayerIdentifier(observer, player_id));
-  UpdateWebContents();
+    players_.insert(PlayerIdentifier(observer, player_id));
+    UpdateWebContents();
+  }
 
+  // Unmute audio for observers which may have started playing asynchronously in
+  // a muted state while waiting for the focus approval.
+  observer->OnSetVolumeMultiplier(player_id, volume_multiplier_);
   return true;
 }
 
@@ -205,27 +205,6 @@ bool MediaSession::IsControllable() const {
          audio_focus_type_ == Type::Content;
 }
 
-void MediaSession::ResetJavaRefForTest() {
-  j_media_session_.Reset();
-}
-
-bool MediaSession::IsActiveForTest() const {
-  return audio_focus_state_ == State::ACTIVE;
-}
-
-MediaSession::Type MediaSession::audio_focus_type_for_test() const {
-  return audio_focus_type_;
-}
-
-MediaSessionUmaHelper* MediaSession::uma_helper_for_test() {
-  return &uma_helper_;
-}
-
-void MediaSession::RemoveAllPlayersForTest() {
-  players_.clear();
-  AbandonSystemAudioFocusIfNeeded();
-}
-
 void MediaSession::OnSuspendInternal(SuspendType type, State new_state) {
   DCHECK(new_state == State::SUSPENDED || new_state == State::INACTIVE);
   // UI suspend cannot use State::INACTIVE.
@@ -289,6 +268,7 @@ void MediaSession::OnSetVolumeMultiplierInternal(double volume_multiplier) {
 
 MediaSession::MediaSession(WebContents* web_contents)
     : WebContentsObserver(web_contents),
+      default_system_audio_focus_response_(true),
       audio_focus_state_(State::INACTIVE),
       audio_focus_type_(Type::Transient),
       volume_multiplier_(media::MediaPlayerAndroid::kDefaultVolumeMultiplier) {
@@ -306,7 +286,7 @@ void MediaSession::Initialize() {
 bool MediaSession::RequestSystemAudioFocus(Type type) {
   // During tests, j_media_session_ might be null.
   if (j_media_session_.is_null())
-    return true;
+    return default_system_audio_focus_response_;
 
   JNIEnv* env = base::android::AttachCurrentThread();
   DCHECK(env);