Revert "Making all DOM types abstract and removing superfluous Dartium constructors."

tools/dom/templates/html/impl/impl_XMLHttpRequest.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;
 
 /**
  * A utility for retrieving data from a URL.
  *
  * HttpRequest can be used to obtain data from http, ftp, and file
@@ skipping 12 matching lines @@
  * port, and application layer protocol) as the URL you are trying to access
  * with HttpRequest. However, there are ways to
  * [get around this restriction](http://www.dartlang.org/articles/json-web-service/#note-on-jsonp).
  *
  * See also:
  *
  * * [Dart article on using HttpRequests](http://www.dartlang.org/articles/json-web-service/#getting-data)
  * * [JS XMLHttpRequest](https://developer.mozilla.org/en-US/docs/DOM/XMLHttpRequest)
  * * [Using XMLHttpRequest](https://developer.mozilla.org/en-US/docs/DOM/XMLHttpRequest/Using_XMLHttpRequest)
  */
-$(ANNOTATIONS)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
+$(ANNOTATIONS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 
   /**
    * Creates a URL get request for the specified [url].
    *
    * The server response must be a `text/` mime type for this request to
    * succeed.
    *
    * This is similar to [request] but specialized for HTTP GET requests which
    * return text content.
    *
@@ skipping 138 matching lines @@
 $if DART2JS
     var xhr = new HttpRequest();
     return JS('bool', '("overrideMimeType" in #)', xhr);
 $else
     return true;
 $endif
   }
 
 $!MEMBERS
 }