Show empty bell icon in notification button initially

ash/common/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/common/system/web_notification/web_notification_tray.h"
 
 #include "ash/common/ash_switches.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shelf/shelf_constants.h"
@@ skipping 121 matching lines @@
           CreateVectorIcon(gfx::VectorIconId::NOTIFICATIONS, kNoUnreadIconSize,
                            kWebNotificationColorNoUnread);
     }
 
     no_unread_icon_.SetImage(image);
     no_unread_icon_.set_owned_by_client();
 
     unread_label_.set_owned_by_client();
     SetupLabelForTray(&unread_label_);
 
-    AddChildView(&unread_label_);
+    AddChildView(&no_unread_icon_);
   }
 
   void SetBubbleVisible(bool visible) {
     if (visible == is_bubble_visible_)
       return;
 
     is_bubble_visible_ = visible;
     UpdateIconVisibility();
   }
 
@@ skipping 377 matching lines @@
 
 message_center::MessageCenterBubble*
 WebNotificationTray::GetMessageCenterBubbleForTest() {
   if (!message_center_bubble())
     return NULL;
   return static_cast<message_center::MessageCenterBubble*>(
       message_center_bubble()->bubble());
 }
 
 }  // namespace ash