Do regular expression for camelCase CSS processing in JS.

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

 
 // Copyright (c) 2014, 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.
 
 // WARNING: DO NOT EDIT THIS TEMPLATE FILE.
 // The template file was generated by scripts/css_code_generator.py
 
 // Source of CSS properties:
 //   CSSPropertyNames.in
@@ skipping 58 matching lines @@
   void setProperty(String propertyName, String value, [String priority]) {
     if (_supportsProperty(_camelCase(propertyName))) {
       return _setPropertyHelper(propertyName, value, priority);
     } else {
       return _setPropertyHelper(Device.cssPrefix + propertyName, value,
           priority);
     }
   }
 
   static String _camelCase(String hyphenated) {
+$if DART2JS
+    var replacedMs = JS('String', r'#.replace(/^-ms-/, "ms-")', hyphenated);
+
+    var fToUpper = const JS_CONST(
+        r'function(_, letter) { return letter.toUpperCase(); }');
+    return JS('String', r'#.replace(/-([\da-z])/ig, #)', replacedMs, fToUpper);
+$else
     // The "ms" prefix is always lowercased.
     return hyphenated.replaceFirst(new RegExp('^-ms-'), 'ms-').replaceAllMapped(
         new RegExp('-([a-z]+)', caseSensitive: false),
         (match) => match[0][1].toUpperCase() + match[0].substring(2));
+$endif
   }
 
 $if DART2JS
   void _setPropertyHelper(String propertyName, String value, [String priority]) {
     // try/catch for IE9 which throws on unsupported values.
     try {
       if (value == null) value = '';
       if (priority == null) {
         priority = '';
       }
@@ skipping 3132 matching lines @@
 
   /** Gets the value of "zoom" */
   String get zoom =>
     getPropertyValue('zoom');
 
   /** Sets the value of "zoom" */
   void set zoom(String value) {
     setProperty('zoom', value, '');
   }
 }