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

chrome/browser/ui/ash/chrome_shell_delegate.cc

Index: chrome/browser/ui/ash/chrome_shell_delegate.cc
diff --git a/chrome/browser/ui/ash/chrome_shell_delegate.cc b/chrome/browser/ui/ash/chrome_shell_delegate.cc
index 9709904ca56a292db2fba3210dee215b7c3dfd9a..c9e7995a1176daf974b2dcb3fcac6171685b7f57 100644
--- a/chrome/browser/ui/ash/chrome_shell_delegate.cc
+++ b/chrome/browser/ui/ash/chrome_shell_delegate.cc
@@ -60,6 +60,7 @@
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/scoped_tabbed_browser_displayer.h"
+#include "chrome/browser/ui/tab_contents/tab_contents_iterator.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/grit/chromium_strings.h"
 #include "chrome/grit/generated_resources.h"
@@ -68,6 +69,7 @@
 #include "components/prefs/pref_service.h"
 #include "components/user_manager/user.h"
 #include "components/user_manager/user_manager.h"
+#include "content/public/browser/media_session.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/common/service_manager_connection.h"
 #include "ui/aura/window.h"
@@ -588,6 +590,13 @@ void ChromeShellDelegate::ToggleTouchpad() {
   chromeos::system::InputDeviceSettings::Get()->ToggleTouchpad();
 }
 
+void ChromeShellDelegate::SuspendMediaSessions() {
+  for (TabContentsIterator it; !it.done(); it.Next()) {
+    content::MediaSession::Get(*it)->Suspend(
+        content::MediaSession::SuspendType::SYSTEM);
+  }
+}
+
 keyboard::KeyboardUI* ChromeShellDelegate::CreateKeyboardUI() {
   return new ChromeKeyboardUI(ProfileManager::GetActiveUserProfile());
 }