MD History: Use one-way binding for history query state.

chrome/browser/resources/md_history/router.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.
 
 Polymer({
   is: 'history-router',
 
   properties: {
     selectedPage: {
       type: String,
       observer: 'serializePath_',
       notify: true,
     },
 
-    /** @type {QueryState} */
-    queryState: {
-      type: Object,
-      notify: true,
-      value: function() {
-        // TODO(tsergeant: Move this initialization into query-manager.
-        return {
-          // Whether the most recent query was incremental.
-          incremental: false,
-          // A query is initiated by page load.
-          querying: true,
-          queryingDisabled: false,
-          _range: HistoryRange.ALL_TIME,
-          searchTerm: '',
-          groupedOffset: 0,
-
-          set range(val) {
-            this._range = Number(val);
-          },
-          get range() {
-            return this._range;
-          },
-        };
-      },
-    },
-
     path_: {
       type: String,
       observer: 'pathChanged_',
     },
 
+    /** @type {QueryState} */
+    queryState: Object,
+
     queryParams_: Object,
   },
 
   observers: [
     'queryParamsChanged_(queryParams_.*)',
     'searchTermChanged_(queryState.searchTerm)',
   ],
 
   /** @override */
   attached: function() {
@@ skipping 11 matching lines @@
   },
 
   /** @private */
   pathChanged_: function() {
     var sections = this.path_.substr(1).split('/');
     this.selectedPage = sections[0] || 'history';
   },
 
   /** @private */
   queryParamsChanged_: function() {
-    this.set('queryState.searchTerm', this.queryParams_.q || '');
+    this.fire('change-query', {search: this.queryParams_.q || ''});
   },
 
   /** @private */
   searchTermChanged_: function() {
     this.set('queryParams_.q', this.queryState.searchTerm || null);
   },
 });