Change eventTime field to standard chrome.* API format.

ui/message_center/notification.h

 // 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.
 
 #ifndef UI_MESSAGE_CENTER_NOTIFICATION_H_
 #define UI_MESSAGE_CENTER_NOTIFICATION_H_
 
 #include <vector>
 
 #include "base/string16.h"
@@ skipping 18 matching lines @@
   ui::notifications::NotificationType type;
   std::string id;
   string16 title;
   string16 message;
   string16 display_source;
   std::string extension_id;
 
   // Begin unpacked values from optional_fields
   int priority;
   base::Time timestamp;
-  int unread_count;
   std::vector<string16> button_titles;
   string16 expanded_message;
   std::vector<NotificationItem> items;
   // End unpacked values
 
   // Images fetched asynchronously
   gfx::ImageSkia primary_icon;
   gfx::ImageSkia image;
   std::vector<gfx::ImageSkia> button_icons;
 
   bool is_read;  // True if this has been seen in the message center
   bool shown_as_popup;  // True if this has been shown as a popup notification
 };
 
 }  // namespace message_center
 
 #endif // UI_MESSAGE_CENTER_NOTIFICATION_H_