Partially migrate from old getter syntax to new one.

lib/dom/templates/html/impl/impl_Storage.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.
 
 class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 
   // TODO(nweiz): update this when maps support lazy iteration
   bool containsValue(String value) => getValues().some((e) => e == value);
 
   bool containsKey(String key) => $dom_getItem(key) != null;
@@ skipping 29 matching lines @@
     forEach((k, v) => keys.add(k));
     return keys;
   }
 
   Collection<String> getValues() {
     final values = [];
     forEach((k, v) => values.add(v));
     return values;
   }
 
-  int get length() => $dom_length;
+  int get length => $dom_length;
 
   bool isEmpty() => $dom_key(0) == null;
 $!MEMBERS
 }