Allow all events to be accessed via on[foo] instead of just onFoo

tools/dom/templates/html/impl/impl_EventTarget.darttemplate

Index: tools/dom/templates/html/impl/impl_EventTarget.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_EventTarget.darttemplate b/tools/dom/templates/html/impl/impl_EventTarget.darttemplate
index 1630878110b9cb4978c19215865912a37fe98437..7451aa58d959e8c447095985f5f939fe773493f2 100644
--- a/tools/dom/templates/html/impl/impl_EventTarget.darttemplate
+++ b/tools/dom/templates/html/impl/impl_EventTarget.darttemplate
@@ -54,10 +54,29 @@ class Events {
 class ElementEvents extends Events {
   /* Raw event target. */
   final Element _ptr;
+  static final webkitEvents = {
+    'fullscreenchange' : 'onwebkitfullscreenchange', 

[blois, 2013/10/19 01:19:10]

the on prefix should not be there.

[Emily Fortuna, 2013/10/21 17:43:51]

Done.

+    'fullscreenerror' : 'onwebkitfullscreenerror',
+    'pointerlockchange' : 'onwebkitpointerlockchange', 
+    'pointerlockerror' : 'onwebkitpointerlockerror', 
+    'keyadded' : 'onwebkitkeyadded', 

[blois, 2013/10/19 01:19:10]

Can we only add the webkit prefix on webkit browsers? Otherwise people could be
passing in valid event names then we screw it up.

[Emily Fortuna, 2013/10/21 17:43:51]

Done.

+    'keyerror' : 'onwebkitkeyerror', 
+    'keymessage' : 'onwebkitkeymessage', 
+    'needkey' : 'onwebkitneedkey', 
+    'resourcetimingbufferfull' : 'onwebkitresourcetimingbufferfull', 

[blois, 2013/10/19 01:19:10]

Looking at this list, there are more renames-
https://code.google.com/p/dart/source/browse/branches/bleeding_edge/dart/pkg/...

[Emily Fortuna, 2013/10/21 17:43:51]

I think those other events much have gone away. I can't find DOMFocusIn/Out in
html at all.

+    'animationend' : 'onwebkitAnimationEnd', 
+    'animationiteration' : 'onwebkitAnimationIteration', 
+    'animationstart' : 'onwebkitAnimationStart', 

[Emily Fortuna, 2013/10/19 00:57:31]

it seemed unrealistic to expect the user to know that "AnimationStart' starts
with a capital letter, but 'needkey' does not, so I made these case insensitive.
If you disagree, then we can just append "onwebkit" to the string and expect the
user to type it correctly.

+    'speechchange' : 'onwebkitSpeechChange'
+  };
 
   ElementEvents(Element ptr) : this._ptr = ptr, super(ptr);
 
   Stream operator [](String type) {
+    if (type.toLowerCase() in webkitEvents.keys) {
+      return new _ElementEventStreamImpl(
+          _ptr, webkitEvents[type.toLowerCase()], false);
+    }
     return new _ElementEventStreamImpl(_ptr, type, false);
   }
 }