Events operator [] shouldn't convert event name to lower case.

lib/dom/templates/html/dartium/impl_EventTarget.darttemplate

Index: lib/dom/templates/html/dartium/impl_EventTarget.darttemplate
diff --git a/lib/dom/templates/html/dartium/impl_EventTarget.darttemplate b/lib/dom/templates/html/dartium/impl_EventTarget.darttemplate
index 18b73540d74f0d719c2ffc14627cebb2d557efb4..a459cdc3a9b5414944063bae593abfa0e4cf9057 100644
--- a/lib/dom/templates/html/dartium/impl_EventTarget.darttemplate
+++ b/lib/dom/templates/html/dartium/impl_EventTarget.darttemplate
@@ -11,10 +11,6 @@ class _EventsImpl implements Events {
   _EventsImpl(this._ptr) : _listenerMap = <EventListenerList>{};
 
   EventListenerList operator [](String type) {
-    return _get(type.toLowerCase());
-  }
-  
-  EventListenerList _get(String type) {
     return _listenerMap.putIfAbsent(type,
       () => new _EventListenerListImpl(_ptr, type));
   }