[MD Bookmarks] Add routing.

chrome/browser/resources/md_bookmarks/router.js

Index: chrome/browser/resources/md_bookmarks/router.js
diff --git a/chrome/browser/resources/md_bookmarks/router.js b/chrome/browser/resources/md_bookmarks/router.js
new file mode 100644
index 0000000000000000000000000000000000000000..ca91000b3f748f82b62d24a3a38333d28fc34202
--- /dev/null
+++ b/chrome/browser/resources/md_bookmarks/router.js
@@ -0,0 +1,55 @@
+// Copyright 2017 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({

[calamity, 2017/01/18 03:37:21]

This element deserves a comment, particularly because it has a one-way bound
interface, so mention that clients initialize themselves by reading the fields
after attach.

[angelayang, 2017/01/18 06:34:02]

Done.

+  is: 'bookmarks-router',
+
+  properties: {
+    /** Path is routed to the selectedId */
+    path: {

[calamity, 2017/01/18 03:37:21]

I think you can make a few of these fields private.

[angelayang, 2017/01/18 06:34:02]

Done.

+      type: String,
+      observer: 'onPathChanged_',
+    },
+
+    /** Parameter is routed to the searchTerm */

[calamity, 2017/01/18 03:37:21]

Use // for non-jsdoc comments.

[angelayang, 2017/01/18 06:34:02]

Done.

+    queryParams: {
+      type: Object,
+    },

[jiaxi, 2017/01/17 05:19:02]

queryParams: Object,

[angelayang, 2017/01/17 05:36:03]

Done.

+
+    searchTerm: {
+      type: String,
+      observer: 'onSearchTermChanged_',
+    },
+
+    /** @type {?string} */
+    selectedId: {
+      type: String,
+      observer: 'onSelectedChanged_',
+    },
+  },
+
+  observers: [
+    'onQueryChanged_(queryParams.*)',
+  ],
+
+  /** @private */
+  onPathChanged_: function() {
+    this.selectedId = this.path.substr(1) || null;
+  },
+
+  /** @private */
+  onQueryChanged_: function() {
+    this.searchTerm = this.queryParams.q || '';
+  },
+
+  /** @private */
+  onSelectedChanged_: function() {
+    this.path = '/' + (this.selectedId || '');
+  },
+
+  /** @private */
+  onSearchTermChanged_: function() {
+    this.set('queryParams.q', this.searchTerm || null);
+  },
+})