MD Settings: Show/hide spinner when searching starts/ends.

chrome/browser/resources/settings/search_settings.js

Index: chrome/browser/resources/settings/search_settings.js
diff --git a/chrome/browser/resources/settings/search_settings.js b/chrome/browser/resources/settings/search_settings.js
index 1b95ac9b25189d4548692ad0d896d7bc7551b1d6..dcf70ff0f297094626066ba7e9f9bd2c8789cd5e 100644
--- a/chrome/browser/resources/settings/search_settings.js
+++ b/chrome/browser/resources/settings/search_settings.js
@@ -358,9 +358,11 @@ cr.define('settings', function() {
         var task = this.popNextTask_();
         if (!task) {
           this.running_ = false;
+          getSearchManager().notifyCallback(false);
           return;
         }
 
+        this.running_ = true;
         window.requestIdleCallback(function() {
           function startNextTask() {
             this.running_ = false;
@@ -389,6 +391,9 @@ cr.define('settings', function() {
 
     /** @private {!SearchContext} */
     this.activeContext_ = {id: 0, rawQuery: null, regExp: null};
+
+    /** @private {?function(boolean):void} */
+    this.callbackFn_ = null;
   };
   cr.addSingletonGetter(SearchManager);
 
@@ -397,6 +402,21 @@ cr.define('settings', function() {
 
   SearchManager.prototype = {
     /**
+     * Registers a callback function that will be called every time search
+     * starts/finishes.
+     * @param {?function(boolean):void} callbackFn
+     */
+    setCallback: function(callbackFn) {
+      this.callbackFn_ = callbackFn;
+    },
+
+    /** @param {boolean} isRunning */
+    notifyCallback: function(isRunning) {
+      if (this.callbackFn_)
+        this.callbackFn_(isRunning);
+    },
+
+    /**
      * @param {string} text The text to search for.
      * @param {!Node} page
      */
@@ -417,6 +437,7 @@ cr.define('settings', function() {
         // Drop all previously scheduled tasks, since a new search was just
         // issued.
         this.queue_.reset();
+        this.notifyCallback(true);
       }
 
       this.queue_.addTopLevelSearchTask(
@@ -424,15 +445,12 @@ cr.define('settings', function() {
     },
   };
 
-  /**
-   * @param {string} text
-   * @param {!Node} page
-   */
-  function search(text, page) {
-    SearchManager.getInstance().search(text, page);
+  /** @return {!SearchManager} */
+  function getSearchManager() {
+    return SearchManager.getInstance();
   }
 
   return {
-    search: search,
+    getSearchManager: getSearchManager,
   };
 });