Fix a type warning for SVGElement.tag.

client/html/frog/html_frog.dart

 #library('html');
 
 // 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.
 
 // DO NOT EDIT
 // Auto-generated dart:html library.
 
 
@@ skipping 31083 matching lines @@
     e.innerHTML = svg;
 
     // Copy list first since we don't want liveness during iteration.
     final List nodes = new List.from(e.nodes);
     fragment.nodes.addAll(nodes);
     return fragment;
   }
 }
 
 class _SVGElementFactoryProvider {
-  factory SVGElement.tag(String tag) =>
-    _document._createElementNS("http://www.w3.org/2000/svg", tag);
+  factory SVGElement.tag(String tag) {
+    final Element temp =
+      _document._createElementNS("http://www.w3.org/2000/svg", tag);
+    return temp;
+  }
 
   factory SVGElement.svg(String svg) {
     Element parentTag;
     final match = _START_TAG_REGEXP.firstMatch(svg);
     if (match != null && match.group(1).toLowerCase() == 'svg') {
       parentTag = new Element.tag('div');
     } else {
       parentTag = new SVGSVGElement();
     }
 
@@ skipping 217 matching lines @@
     if (length < 0) throw new IllegalArgumentException('length');
     if (start < 0) throw new IndexOutOfRangeException(start);
     int end = start + length;
     if (end > a.length) throw new IndexOutOfRangeException(end);
     for (int i = start; i < end; i++) {
       accumulator.add(a[i]);
     }
     return accumulator;
   }
 }