Making HiddenInputElement implement InputElementBase.

tools/dom/templates/html/impl/impl_HTMLInputElement.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;
 
 $(ANNOTATIONS)class $CLASSNAME$EXTENDS implements
     HiddenInputElement,
     SearchInputElement,
     TextInputElement,
@@ skipping 25 matching lines @@
         e.type = type;
       } catch(_) {}
     }
     return e;
   }
 $!MEMBERS
 }
 
 
 // Interfaces representing the InputElement APIs which are supported
-// for the various types of InputElement.
-// From http://dev.w3.org/html5/spec/the-input-element.html#the-input-element.
+// for the various types of InputElement. From:
+// http://www.w3.org/html/wg/drafts/html/master/forms.html#the-input-element.
 
 /**
  * Exposes the functionality common between all InputElement types.
  */
 abstract class InputElementBase implements Element {
   @DomName('HTMLInputElement.autofocus')
   bool autofocus;
 
   @DomName('HTMLInputElement.disabled')
   bool disabled;
@@ skipping 25 matching lines @@
   @DomName('HTMLInputElement.checkValidity')
   bool checkValidity();
 
   @DomName('HTMLInputElement.setCustomValidity')
   void setCustomValidity(String error);
 }
 
 /**
  * Hidden input which is not intended to be seen or edited by the user.
  */
-abstract class HiddenInputElement implements Element {
+abstract class HiddenInputElement implements InputElementBase {
   factory HiddenInputElement() => new InputElement(type: 'hidden');
 }
 
 
 /**
  * Base interface for all inputs which involve text editing.
  */
 abstract class TextInputElementBase implements InputElementBase {
   @DomName('HTMLInputElement.autocomplete')
   String autocomplete;
@@ skipping 485 matching lines @@
   factory ResetButtonInputElement() => new InputElement(type: 'reset');
 }
 
 /**
  * A button, with no default behavior.
  */
 abstract class ButtonInputElement implements InputElementBase {
   factory ButtonInputElement() => new InputElement(type: 'button');
 }