Allow partial update for notification update API

chrome/browser/notifications/notification_ui_manager_impl.cc

Index: chrome/browser/notifications/notification_ui_manager_impl.cc
diff --git a/chrome/browser/notifications/notification_ui_manager_impl.cc b/chrome/browser/notifications/notification_ui_manager_impl.cc
index 6e15592f004e9a36938be8c9c0a3a76d3bdcf316..d2b08d02f53a8aca2464572b79766165d5c16d5a 100644
--- a/chrome/browser/notifications/notification_ui_manager_impl.cc
+++ b/chrome/browser/notifications/notification_ui_manager_impl.cc
@@ -74,13 +74,15 @@ void NotificationUIManagerImpl::Add(const Notification& notification,
   CheckAndShowNotifications();
 }
 
-bool NotificationUIManagerImpl::DoesIdExist(const std::string& id) {
-  for (NotificationDeque::iterator iter = show_queue_.begin();
+const Notification* NotificationUIManagerImpl::FindById(
+    const std::string& id) const {
+  for (NotificationDeque::const_iterator iter = show_queue_.begin();
        iter != show_queue_.end(); ++iter) {
-    if ((*iter)->notification().notification_id() == id)
-      return true;
+    if ((*iter)->notification().notification_id() == id) {
+      return &((*iter)->notification());
+    }
   }
-  return false;
+  return NULL;
 }
 
 bool NotificationUIManagerImpl::CancelById(const std::string& id) {