cros: Suspend media sessions with display off trigger by tablet power button

content/browser/media/session/media_session_controllers_manager.cc

 // Copyright 2016 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_controllers_manager.h"
 
 #include "base/command_line.h"
 #include "content/browser/media/session/media_session_controller.h"
 #include "media/base/media_switches.h"
 
 namespace content {
 
 namespace {
 
 bool IsMediaSessionEnabled() {
-#if defined(OS_ANDROID)
+// Media session is enabled on Android and Chrome OS to allow control of media
+// players as needed.
+#if defined(OS_ANDROID) || defined(OS_CHROMEOS)
   return true;
 #else
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   return command_line->HasSwitch(switches::kEnableInternalMediaSession) ||
          command_line->HasSwitch(switches::kEnableAudioFocus);
 #endif
 }
 
 }  // anonymous namespace
 
@@ skipping 60 matching lines @@
   it->second->OnPlaybackPaused();
 }
 
 void MediaSessionControllersManager::OnEnd(const MediaPlayerId& id) {
   if (!IsMediaSessionEnabled())
     return;
   controllers_map_.erase(id);
 }
 
 }  // namespace content