Added support for image notifications.

ui/message_center/notification_list.cc

Index: ui/message_center/notification_list.cc
diff --git a/ui/message_center/notification_list.cc b/ui/message_center/notification_list.cc
index 4add984f2e078a643c6cfa06f1538898af561396..d92051a7ee1510a71dcd22d180636800d94637f7 100644
--- a/ui/message_center/notification_list.cc
+++ b/ui/message_center/notification_list.cc
@@ -201,6 +201,15 @@ bool NotificationList::SetNotificationSecondaryIcon(
   return true;
 }
 
+bool NotificationList::SetNotificationImage(const std::string& id,
+                                            const gfx::ImageSkia& image) {
+  Notifications::iterator iter;
+  if (!GetNotification(id, &iter))
+    return false;
+  iter->image = image;
+  return true;
+}
+
 bool NotificationList::HasNotification(const std::string& id) {
   Notifications::iterator dummy;
   return GetNotification(id, &dummy);