Allow partial update for notification update API

ui/message_center/notification.cc

 // Copyright (c) 2013 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 "ui/message_center/notification.h"
 
 #include "base/logging.h"
 #include "ui/message_center/notification_types.h"
 
 namespace {
@@ skipping 23 matching lines @@
       never_timeout(other.never_timeout),
       timestamp(other.timestamp),
       expanded_message(other.expanded_message),
       image(other.image),
       items(other.items),
       progress(other.progress),
       buttons(other.buttons) {}
 
 RichNotificationData::~RichNotificationData() {}
 
+Notification::Notification() {

[dewittj, 2013/07/24 23:09:53]

Doesn't this need defaults for all the member variables?

[jianli, 2013/07/25 01:02:41]

Removed.

+}
+
 Notification::Notification(NotificationType type,
                            const std::string& id,
                            const string16& title,
                            const string16& message,
                            const gfx::Image& icon,
                            const string16& display_source,
                            const std::string& extension_id,
                            const RichNotificationData& optional_fields,
                            NotificationDelegate* delegate)
     : type_(type),
@@ skipping 56 matching lines @@
     return;
   optional_fields_.buttons[index].icon = icon;
 }
 
 void Notification::SetSystemPriority() {
   optional_fields_.priority = SYSTEM_PRIORITY;
   optional_fields_.never_timeout = true;
 }
 
 }  // namespace message_center