Made notification center notifications collapsed and expandable.

ui/message_center/notification_list.h

Index: ui/message_center/notification_list.h
diff --git a/ui/message_center/notification_list.h b/ui/message_center/notification_list.h
index 77da6491bb788ca1f4f764ffea930fc2fddb99c5..a7b38b5270df2d77eeb04229528b6609d8539af2 100644
--- a/ui/message_center/notification_list.h
+++ b/ui/message_center/notification_list.h
@@ -66,16 +66,16 @@ class MESSAGE_CENTER_EXPORT NotificationList {
     // Called when a notification is clicked on.
     virtual void OnNotificationClicked(const std::string& id) = 0;
 
-    // Called when the quiet mode status has been changed.
-    virtual void OnQuietModeChanged(bool quiet_mode) = 0;
-
     // Called when a button in a notification is clicked. |button_index|
     // indicates which button was clicked, zero-indexed (button one is 0,
     // button two is 1).
     virtual void OnButtonClicked(const std::string& id, int button_index) = 0;
 
-    // Returns the list of notifications to display.
-    virtual NotificationList* GetNotificationList() = 0;
+    // Called when a notification has been expanded in the notification center.
+    virtual void OnExpand(const std::string& id) = 0;
+
+    // Called when the quiet mode status has been changed.
+    virtual void OnQuietModeChanged(bool quiet_mode) = 0;

[dharcourt, 2013/03/01 10:17:31]

GetNotificationList() was removed because it caused too much coupling between
MessageCenter's NotificationList and objects that had a
NotificationList::Delegate.

As it turns out all objects calling GetNotificationList() were directly coupled
to the MessageCenter so it was easy to modify them to call MessageCenter's
notification_list() accessor directly instead of calling GetNotificationList().
GetNotificationList() could therefor be removed.

   };
 
   explicit NotificationList(Delegate* delegate);
@@ -139,6 +139,9 @@ class MESSAGE_CENTER_EXPORT NotificationList {
   void MarkSinglePopupAsShown(const std::string& id,
                               bool mark_notification_as_read);
 
+  // Marks the specified notification as expanded in the notification center.
+  void MarkNotificationAsExpanded(const std::string& id);
+
   bool quiet_mode() const { return quiet_mode_; }
 
   // Sets the current quiet mode status to |quiet_mode|. The new status is not