Move matches method so that it gets generated for dart2js and dartium.

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

 // 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.
 
 part of $LIBRARYNAME;
 
 class _ChildrenElementList extends ListBase<Element> {
   // Raw Element.
   final Element _element;
   final HtmlCollection _childElements;
@@ skipping 854 matching lines @@
       case 'beforeend':
         this.append(node);
         break;
       case 'afterend':
         this.parentNode.insertBefore(node, this.nextNode);
         break;
       default:
         throw new ArgumentError("Invalid position ${where}");
     }
   }
+$endif
 
   /**
    * Checks if this element matches the CSS selectors.
    */
   @Experimental()
   bool matches(String selectors) {
     if (JS('bool', '!!#.matches', this)) {
       return JS('bool', '#.matches(#)', this, selectors);
     } else if (JS('bool', '!!#.webkitMatchesSelector', this)) {
       return JS('bool', '#.webkitMatchesSelector(#)', this, selectors);
     } else if (JS('bool', '!!#.mozMatchesSelector', this)) {
       return JS('bool', '#.mozMatchesSelector(#)', this, selectors);
     } else if (JS('bool', '!!#.msMatchesSelector', this)) {
       return JS('bool', '#.msMatchesSelector(#)', this, selectors);
     }
     throw new UnsupportedError("Not supported on this platform");
   }
-$else
-$endif
 
 $if DART2JS
   @Creates('Null')  // Set from Dart code; does not instantiate a native type.
 $endif
   Element _templateInstanceRef;
 
   // Note: only used if `this is! TemplateElement`
 $if DART2JS
   @Creates('Null')  // Set from Dart code; does not instantiate a native type.
 $endif
@@ skipping 392 matching lines @@
   const ScrollAlignment._internal(this._value);
   toString() => 'ScrollAlignment.$_value';
 
   /// Attempt to align the element to the top of the scrollable area.
   static const TOP = const ScrollAlignment._internal('TOP');
   /// Attempt to center the element in the scrollable area.
   static const CENTER = const ScrollAlignment._internal('CENTER');
   /// Attempt to align the element to the bottom of the scrollable area.
   static const BOTTOM = const ScrollAlignment._internal('BOTTOM');
 }