Bug 1605798 - part2 : remove unused functions r=chunmin

We have no plan to use those functions, so remove them in order to keep code clean.

Differential Revision: https://phabricator.services.mozilla.com/D58172

--HG--
extra : moz-landing-system : lando

dom/media/mediacontrol/MediaControlService.cpp

@@ -131,27 +131,6 @@ void MediaControlService::RemoveMediaController(MediaController* aController) {
   mMediaControllerAmountChangedEvent.Notify(GetControllersNum());
 }
 
-void MediaControlService::PlayAllControllers() const {
-  for (auto iter = mControllers.ConstIter(); !iter.Done(); iter.Next()) {
-    const RefPtr<MediaController>& controller = iter.Data();
-    controller->Play();
-  }
-}
-
-void MediaControlService::PauseAllControllers() const {
-  for (auto iter = mControllers.ConstIter(); !iter.Done(); iter.Next()) {
-    const RefPtr<MediaController>& controller = iter.Data();
-    controller->Pause();
-  }
-}
-
-void MediaControlService::StopAllControllers() const {
-  for (auto iter = mControllers.ConstIter(); !iter.Done(); iter.Next()) {
-    const RefPtr<MediaController>& controller = iter.Data();
-    controller->Stop();
-  }
-}
-
 void MediaControlService::ShutdownAllControllers() const {
   for (auto iter = mControllers.ConstIter(); !iter.Done(); iter.Next()) {
     const RefPtr<MediaController>& controller = iter.Data();

dom/media/mediacontrol/MediaControlService.h

@@ -65,9 +65,6 @@ class MediaControlService final : public nsIObserver {
   void Init();
   void Shutdown();
 
-  void PlayAllControllers() const;
-  void PauseAllControllers() const;
-  void StopAllControllers() const;
   void ShutdownAllControllers() const;
 
   nsDataHashtable<nsUint64HashKey, RefPtr<MediaController>> mControllers;