Remove numeric hinttext.

ui/keyboard/resources/elements/kb-keyset.html

 <!--
   -- Copyright 2013 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.
   -->
 
-<polymer-element name="kb-keyset" attributes="align isDefault nextKeyset pitch
-    weightRight weightTop weightBottom" on-key-up="{{keyUp}}"
+<polymer-element name="kb-keyset" attributes="align flick isDefault nextKeyset
+    pitch weightRight weightTop weightBottom" on-key-up="{{keyUp}}"
     on-key-longpress="{{keyLongpress}}">
   <template>
     <style>
       :host(:not(.activeKeyset)) {
         display: none;
       }
     </style>
     <content select="kb-row"></content>
     <content select="kb-altkey-container" id="altkeyContainer"
         touch-action="none"></content>
     <kb-altkey-data id="altkeyMetadata"></kb-altkey-data>
   </template>
 </polymer-element>