MD WebUI: Remove local DOM access from CrSearchFieldBehavior

ui/webui/resources/cr_elements/cr_search_field/cr_search_field_behavior.js

Index: ui/webui/resources/cr_elements/cr_search_field/cr_search_field_behavior.js
diff --git a/ui/webui/resources/cr_elements/cr_search_field/cr_search_field_behavior.js b/ui/webui/resources/cr_elements/cr_search_field/cr_search_field_behavior.js
index d6a68d5919f0a622933cadaf8c3a1f65d3c0a3f5..51304c0b2af870166ce30f168e1ea999478440f0 100644
--- a/ui/webui/resources/cr_elements/cr_search_field/cr_search_field_behavior.js
+++ b/ui/webui/resources/cr_elements/cr_search_field/cr_search_field_behavior.js
@@ -35,10 +35,17 @@ var CrSearchFieldBehavior = {
   },
 
   /**
+   * @abstract
+   * @return {!HTMLInputElement} The input field element the behavior should
+   * use.
+   */
+  getSearchInput: function() {},
+
+  /**
    * @return {string} The value of the search field.
    */
   getValue: function() {
-    return this.$.searchInput.value;
+    return this.getSearchInput().value;
   },
 
   /**
@@ -48,7 +55,7 @@ var CrSearchFieldBehavior = {
   setValue: function(value) {
     // Use bindValue when setting the input value so that changes propagate
     // correctly.
-    this.$.searchInput.bindValue = value;
+    this.getSearchInput().bindValue = value;
     this.onValueChanged_(value);
   },
 
@@ -59,7 +66,7 @@ var CrSearchFieldBehavior = {
 
   /** @private */
   focus_: function() {
-    this.$.searchInput.focus();
+    this.getSearchInput().focus();
   },
 
   onSearchTermSearch: function() {
@@ -93,11 +100,6 @@ var CrSearchFieldBehavior = {
     }
 
     this.setValue('');
-    this.$.searchInput.blur();
-  },
-
-  /** @return {boolean} */
-  isSearchFocused: function() {
-    return this.$.searchTerm.focused;
+    this.getSearchInput().blur();
   }
 };