console.error when using unknown attributes in templates.

sky/examples/city-list/city-list.sky

 <!--
 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 -->
 <import src="../../framework/sky-element/sky-element.sky" as="SkyElement" />
 <import src="city-data-service.sky" as="CityDataService" />
 <import src="city-sequence.sky" as="CitySequence" />
 
 <script>
@@ skipping 144 matching lines @@
     display: none;
   }
 
   .position {
     position: absolute;
     left: 0;
     right: 0;
   }
 
   </style>
-  <div id="scroller" fit>
+  <div id="scroller">
     <div id="scrollarea">
       <div id="contentarea">
       </div>
     </div>
   </div>
 </template>
 <script>
 
 (function(global) {
     "use strict";
@@ skipping 443 matching lines @@
 
       scrollBy(amount) {
         this.scrollerElement.scrollTop += amount;
         this.handleScroll({ target: this.scrollerElement });
       }
     }.register();
 
 })(this);
 </script>
 </sky-element>