MD WebUI: Remove local DOM access from CrSearchFieldBehavior

ui/webui/resources/cr_elements/cr_toolbar/cr_toolbar_search_field.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.
 
 // TODO(tsergeant): Add tests for cr-toolbar-search-field.
 Polymer({
   is: 'cr-toolbar-search-field',
 
   behaviors: [CrSearchFieldBehavior],
 
@@ skipping 18 matching lines @@
 
     /** @private */
     hasSearchText_: Boolean,
   },
 
   listeners: {
     'tap': 'showSearch_',
     'searchInput.bind-value-changed': 'onBindValueChanged_',
   },
 
+  /** @return {!HTMLInputElement} */
+  getSearchInput: function() {
+    return this.$.searchInput;
+  },
+
+  /** @return {boolean} */
+  isSearchFocused: function() {
+    return this.$.searchTerm.focused;
+  },
+
   /**
    * @param {boolean} narrow
    * @return {number}
    * @private
    */
   computeIconTabIndex_: function(narrow) {
     return narrow ? 0 : -1;
   },
 
   /**
@@ skipping 36 matching lines @@
 
   /**
    * @param {Event} e
    * @private
    */
   hideSearch_: function(e) {
     this.showingSearch = false;
     e.stopPropagation();
   }
 });