Rename XMLHttpRequest to HttpRequest.

tests/html/event_test.dart

 // Copyright (c) 2011, 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.
 
 #library('EventTest');
 #import('../../pkg/unittest/unittest.dart');
 #import('../../pkg/unittest/html_config.dart');
 #import('dart:html');
 
 // TODO(nweiz): Make this private to testEvents when Frog supports closures with
@@ skipping 196 matching lines @@
     Expect.equals(3, ev.screenX);
     Expect.equals(4, ev.screenY);
     Expect.equals(5, ev.clientX);
     Expect.equals(6, ev.clientY);
     Expect.isTrue(ev.ctrlKey);
     Expect.isTrue(ev.altKey);
     Expect.isTrue(ev.shiftKey);
     Expect.isTrue(ev.metaKey);
   }, type: 'mousewheel');
 
-  // XMLHttpRequestProgressEvent has no properties to itself, so just test that
+  // HttpRequestProgressEvent has no properties to itself, so just test that
   // it doesn't error out on creation and can be dispatched.
   // Issue 1005.
-  // eventTest('XMLHttpRequestProgressEvent',
-  //     () => new XMLHttpRequestProgressEvent('foo', 5),
+  // eventTest('HttpRequestProgressEvent',
+  //     () => new HttpRequestProgressEvent('foo', 5),
   //     (ev) {});
 }