[MD Bookmarks] Add skeleton for MD Bookmarks.

chrome/test/data/webui/md_bookmarks/test_util.js

Index: chrome/test/data/webui/md_bookmarks/test_util.js
diff --git a/chrome/test/data/webui/md_bookmarks/test_util.js b/chrome/test/data/webui/md_bookmarks/test_util.js
new file mode 100644
index 0000000000000000000000000000000000000000..84c1a6bb185c370fa4494ea8f59f2e62df472543
--- /dev/null
+++ b/chrome/test/data/webui/md_bookmarks/test_util.js
@@ -0,0 +1,12 @@
+// 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.
+
+/**
+ * Replace the current body of the test with a new element.
+ * @param {Element} element
+ */
+function replaceBody(element) {
+  PolymerTest.clearBody();
+  document.body.appendChild(element);
+}