Update hide keyboard label.

ui/keyboard/resources/elements/kb-options-menu.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-options-menu-item" attributes="layout label active"
     on-pointerup="up" on-pointerover="over" on-pointerout="out">
   <template>
     <style>
@@ skipping 92 matching lines @@
     <!-- TODO(kevers): This is a temporary placeholder to enable testing
       -- of layout switching.  Deprecate once a decision is reached on
       -- a more permanent solution for layout selection. -->
     <kb-options-menu-toggle-lock-item></kb-options-menu-toggle-lock-item>
     <kb-options-menu-item layout="system-qwerty" label="System QWERTY">
     </kb-options-menu-item>
     <kb-options-menu-item layout="qwerty" label="QWERTY">
     </kb-options-menu-item>
     <kb-options-menu-item layout="dvorak" label="Dvorak">
     </kb-options-menu-item>
-    <kb-options-menu-item layout="none" label="Hide keyboard">
+    <kb-options-menu-item layout="none" label="Hide">
     </kb-options-menu-item>
   </template>
 </polymer-element>
 
 <polymer-element name="kb-keyboard-overlay" attributes="keyset"
     on-pointerup="up">
   <template>
     <style>
       :host {
           background-color: rgba(0, 0, 0, 0.6);
@@ skipping 16 matching lines @@
 
       hiddenChanged: function() {
         this.fire('stateChange', {
           state: 'overlayVisibility',
           value: !!this.hidden
         });
       }
     });
   </script>
 </polymer-element>