Add touchenter event even though it doesn't have an ontouchenter method in the DOM.

lib/dom/scripts/systemhtml.py

 #!/usr/bin/python
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 """This module provides shared functionality for the system to generate
 Dart:html APIs from the IDL database."""
 
 from systemfrog import *
 from systeminterface import *
@@ skipping 257 matching lines @@
     "Node.get:PROCESSING_INSTRUCTION_NODE",
     "Notification.dispatchEvent",
     "Notification.addEventListener",
     "Notification.removeEventListener"])
 
 # Events without onEventName attributes in the  IDL we want to support.
 # We can automatically extract most event event names by checking for
 # onEventName methods in the IDL but some events aren't listed so we need
 # to manually add them here so that they are easy for users to find.
 _html_manual_events = {
-  'Element': ['touchleave', 'webkitTransitionEnd'],
+  'Element': ['touchleave', 'touchenter', 'webkitTransitionEnd'],
   'Window': ['DOMContentLoaded']
 }
 
 # These event names must be camel case when attaching event listeners
 # using addEventListener even though the onEventName properties in the DOM for
 # them are not camel case.
 _on_attribute_to_event_name_mapping = {
   'webkitanimationend': 'webkitAnimationEnd',
   'webkitanimationiteration': 'webkitAnimationIteration',
   'webkitanimationstart': 'webkitAnimationStart',
@@ skipping 83 matching lines @@
   'selectionchange': 'selectionChange',
   'selectstart': 'selectStart',
   'show': 'show',
   'stalled': 'stalled',
   'storage': 'storage',
   'submit': 'submit',
   'suspend': 'suspend',
   'timeupdate': 'timeUpdate',
   'touchcancel': 'touchCancel',
   'touchend': 'touchEnd',
+  'touchenter': 'touchEnter',
   'touchmove': 'touchMove',
   'touchstart': 'touchStart',
   'unload': 'unload',
   'updateready': 'updateReady',
   'volumechange': 'volumeChange',
   'waiting': 'waiting',
   'webkitAnimationEnd': 'animationEnd',
   'webkitAnimationIteration': 'animationIteration',
   'webkitAnimationStart': 'animationStart',
   'webkitfullscreenchange': 'fullscreenChange',
@@ skipping 1253 matching lines @@
     # dispatch has removed f(X), leaving only f(Y), but there is no guarantee
     # that Y = Z-X, so we need to check for Y.
     true_code = emitter.Emit(
         '$(INDENT)if ($COND) {\n'
         '$!TRUE'
         '$(INDENT)}\n',
         COND=test, INDENT=indent)
     self.GenerateDispatch(
         true_code, info, indent + '  ', position + 1, positive)
     return True