Implement support for silent notifications.

content/public/common/platform_notification_data.h

 // Copyright 2014 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.
 
 #ifndef CONTENT_PUBLIC_COMMON_PLATFORM_NOTIFICATION_DATA_H_
 #define CONTENT_PUBLIC_COMMON_PLATFORM_NOTIFICATION_DATA_H_
 
 #include <string>
 
 #include "base/strings/string16.h"
@@ skipping 27 matching lines @@
 
   // Contents of the notification.
   base::string16 body;
 
   // Tag of the notification. Notifications sharing both their origin and their
   // tag will replace the first displayed notification.
   base::string16 tag;
 
   // URL of the icon which is to be displayed with the notification.
   GURL icon;
+
+  // Whether default notification indicators (sound, vibration, light) should
+  // be suppressed.
+  bool silent;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_PLATFORM_NOTIFICATION_DATA_H_