Make MediaSession a runtime-enabled feature on Desktop.

content/browser/media/android/browser_media_player_manager.cc

 // Copyright 2013 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/android/browser_media_player_manager.h"
 
 #include <utility>
 
 #include "base/android/scoped_java_ref.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
 #include "content/browser/media/android/browser_demuxer_android.h"
 #include "content/browser/media/android/media_resource_getter_impl.h"
-#include "content/browser/media/android/media_session.h"
 #include "content/browser/media/android/media_throttler.h"
 #include "content/browser/media/android/media_web_contents_observer_android.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/common/media/media_player_messages_android.h"
 #include "content/public/browser/android/external_video_surface_container.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/render_frame_host.h"
@@ skipping 716 matching lines @@
   if (!player)
     return;
   player->Start();
   if (fullscreen_player_id_ == player_id && fullscreen_player_is_released_) {
     video_view_->OpenVideo();
     fullscreen_player_is_released_ = false;
   }
 }
 
 }  // namespace content