MD History: Display synced tabs history.

chrome/browser/resources/md_history/side_bar.js

Index: chrome/browser/resources/md_history/side_bar.js
diff --git a/chrome/browser/resources/md_history/side_bar.js b/chrome/browser/resources/md_history/side_bar.js
new file mode 100644
index 0000000000000000000000000000000000000000..1f14c5b452f956262d51a80b565e0122e913f7d8
--- /dev/null
+++ b/chrome/browser/resources/md_history/side_bar.js
@@ -0,0 +1,18 @@
+// 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: 'side-bar',
+
+  changeDisplay: function(e) {
+    var currentSelectedButton =
+        Polymer.dom(this.root).querySelector('.selected');
+    currentSelectedButton.classList.remove('selected');
+
+    e.currentTarget.classList.add('selected');
+
+    this.fire('switch-display', { display: e.currentTarget.id });
+  },
+
+});