[MD Settings] Implement search in material design passwords.

chrome/browser/resources/settings/settings_page/settings_subpage_search.js

 // Copyright 2016 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.
 
 /**
  * @fileoverview
  * 'settings-subpage' shows a subpage beneath a subheader. The header contains
  * the subpage title and a back icon. The back icon fires an event which
  * is caught by settings-animated-pages, so it requires no separate handling.
  */
 
 Polymer({
-  is: 'settings-subpage',
+  is: 'settings-subpage-search',
 
-  behaviors: [
-    // TODO(michaelpg): phase out NeonAnimatableBehavior.
-    Polymer.NeonAnimatableBehavior,
-    Polymer.IronResizableBehavior,
-  ],
-
-  properties: {
-    pageTitle: String,
-  },
+  behaviors: [CrSearchFieldBehavior],
 
   /** @private */
-  onTapBack_: function() {
-    // Event is caught by settings-animated-pages.
-    this.fire('subpage-back');
+  onTapClear_: function() {
+    this.setValue('');
   },
 });