[MD History] Unify query state in history-app.

chrome/browser/resources/md_history/history_toolbar.js

 // Copyright 2015 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.
 
 /**
  * @constructor
  * @implements {SearchFieldDelegate}
  * @param {!HistoryToolbarElement} toolbar This history-toolbar.
  */
 function ToolbarSearchFieldDelegate(toolbar) {
@@ skipping 22 matching lines @@
     itemsSelected_: {
       type: Boolean,
       value: false,
       reflectToAttribute: true
     },
 
     // The most recent term entered in the search field. Updated incrementally
     // as the user types.
     searchTerm: {
       type: String,
-      value: ''
+      notify: true,
     },
 
     // True if waiting on the search backend.
     searching: {
       type: Boolean,
       value: false
     },
 
     // Whether domain-grouped history is enabled.
     isGroupedMode: {
@@ skipping 25 matching lines @@
   },
 
   /**
    * When changing the search term externally, update the search field to
    * reflect the new search term.
    * @param {string} search
    */
   setSearchTerm: function(search) {
     if (this.searchTerm == search)
       return;
+
     this.searchTerm = search;
     var searchField = /** @type {SearchField} */(this.$['search-input']);
     searchField.showAndFocus().then(function(showing) {
       if (showing) searchField.setValue(search);
     });
   },
 
   /**
    * If the search term has changed reload for the new search.
    */
   onSearch: function(searchTerm) {
-    if (searchTerm != this.searchTerm) {
+    if (searchTerm != this.searchTerm)
       this.searchTerm = searchTerm;
-      this.fire('search-changed', {search: searchTerm});
-    }
   },
 
   attached: function() {
     this.searchFieldDelegate_ = new ToolbarSearchFieldDelegate(this);
     /** @type {SearchField} */(this.$['search-input'])
         .setDelegate(this.searchFieldDelegate_);
   },
 
   onClearSelectionTap_: function() {
     this.fire('unselect-all');
@@ skipping 14 matching lines @@
   numberOfItemsSelected_: function(count) {
     return count > 0 ? loadTimeData.getStringF('itemsSelected', count) : '';
   },
 
   getHistoryInterval_: function(queryStartTime, queryEndTime) {
     // TODO(calamity): Fix the format of these dates.
     return loadTimeData.getStringF(
       'historyInterval', queryStartTime, queryEndTime);
   }
 });