mash: Close the system tray bubble on click outside its bounds

ash/system/web_notification/web_notification_tray.cc

 // Copyright (c) 2012 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 "ash/system/web_notification/web_notification_tray.h"
 
 #include "ash/ash_switches.h"
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shelf/shelf_layout_manager_observer.h"
@@ skipping 440 matching lines @@
                                ->session_state_delegate()
                                ->IsInSecondaryLoginScreen();
 
   SetVisible((status_area_widget()->login_status() != user::LOGGED_IN_NONE) &&
              (status_area_widget()->login_status() != user::LOGGED_IN_LOCKED) &&
              !userAddingRunning && (message_center->NotificationCount() > 0));
   Layout();
   SchedulePaint();
 }
 
-bool WebNotificationTray::ClickedOutsideBubble() {
+void WebNotificationTray::ClickedOutsideBubble() {
   // Only hide the message center
   if (!message_center_bubble())
-    return false;
+    return;
 
   message_center_tray_->HideMessageCenterBubble();
-  return true;
 }
 
 message_center::MessageCenter* WebNotificationTray::message_center() const {
   return message_center_tray_->message_center();
 }
 
 // Methods for testing
 
 bool WebNotificationTray::IsPopupVisible() const {
   return message_center_tray_->popups_visible();
 }
 
 message_center::MessageCenterBubble*
 WebNotificationTray::GetMessageCenterBubbleForTest() {
   if (!message_center_bubble())
     return NULL;
   return static_cast<message_center::MessageCenterBubble*>(
       message_center_bubble()->bubble());
 }
 
 }  // namespace ash