[Chromecast] Fix media session blocking tests.

content/browser/media/session/media_session_impl.cc

 // 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.
 
 #include "content/browser/media/session/media_session_impl.h"
 
 #include <algorithm>
 #include "content/browser/media/session/audio_focus_delegate.h"
 #include "content/browser/media/session/media_session_controller.h"
 #include "content/browser/media/session/media_session_player_observer.h"
@@ skipping 74 matching lines @@
     session->Initialize();
   }
   return session;
 }
 
 MediaSessionImpl::~MediaSessionImpl() {
   DCHECK(normal_players_.empty());
   DCHECK(pepper_players_.empty());
   DCHECK(one_shot_players_.empty());
   DCHECK(audio_focus_state_ == State::INACTIVE);
-  for (auto& observer : observers_)
+  for (auto& observer : observers())
     observer.MediaSessionDestroyed();
 }
 
 void MediaSessionImpl::WebContentsDestroyed() {
   // This should only work for tests. In production, all the players should have
   // already been removed before WebContents is destroyed.
 
   // TODO(zqzhang): refactor MediaSessionImpl, maybe move the interface used to
   // talk with AudioFocusManager out to a seperate class. The AudioFocusManager
   // unit tests then could mock the interface and abandon audio focus when
   // WebContents is destroyed. See https://crbug.com/651069
   normal_players_.clear();
   pepper_players_.clear();
   one_shot_players_.clear();
   AbandonSystemAudioFocusIfNeeded();
 }
 
-void MediaSessionImpl::AddObserver(MediaSessionObserver* observer) {
-  observers_.AddObserver(observer);
-}
-
-void MediaSessionImpl::RemoveObserver(MediaSessionObserver* observer) {
-  observers_.RemoveObserver(observer);
-}
-
 void MediaSessionImpl::NotifyMediaSessionMetadataChange(
     const base::Optional<MediaMetadata>& metadata) {
-  for (auto& observer : observers_)
+  for (auto& observer : observers())
     observer.MediaSessionMetadataChanged(metadata);
 }
 
 void MediaSessionImpl::NotifyMediaSessionActionsChange(
     const std::set<blink::mojom::MediaSessionAction>& actions) {
-  for (auto& observer : observers_)
+  for (auto& observer : observers())
     observer.MediaSessionActionsChanged(actions);
 }
 
 bool MediaSessionImpl::AddPlayer(MediaSessionPlayerObserver* observer,
                                  int player_id,
                                  media::MediaContentType media_content_type) {
   if (media_content_type == media::MediaContentType::OneShot)
     return AddOneShotPlayer(observer, player_id);
   if (media_content_type == media::MediaContentType::Pepper)
     return AddPepperPlayer(observer, player_id);
@@ skipping 377 matching lines @@
   //
   // TODO(zqzhang): Maybe also compute for IsControllable()? See
   // https://crbug.com/674983
   if (routed_service_ &&
       routed_service_->playback_state() ==
           blink::mojom::MediaSessionPlaybackState::PLAYING) {
     is_actually_suspended = false;
   }
 
   media_session_state_listeners_.Notify(audio_focus_state_);
-  for (auto& observer : observers_)
+  for (auto& observer : observers())
     observer.MediaSessionStateChanged(IsControllable(), is_actually_suspended);
 }
 
 void MediaSessionImpl::SetAudioFocusState(State audio_focus_state) {
   if (audio_focus_state == audio_focus_state_)
     return;
 
   audio_focus_state_ = audio_focus_state;
   switch (audio_focus_state_) {
     case State::ACTIVE:
@@ skipping 130 matching lines @@
     if (!IsServiceActiveForRenderFrameHost(frame))
       continue;
     best_frame = frame;
     min_depth = depth;
   }
 
   return best_frame ? services_[best_frame] : nullptr;
 }
 
 }  // namespace content