Improve JS unit tests.

remoting/webapp/browser_globals.gtestjs

Index: remoting/webapp/browser_globals.gtestjs
diff --git a/remoting/webapp/browser_globals.gtestjs b/remoting/webapp/browser_globals.gtestjs
new file mode 100644
index 0000000000000000000000000000000000000000..0d55b25376e87400c429e8064c3d7e969e0244f8
--- /dev/null
+++ b/remoting/webapp/browser_globals.gtestjs
@@ -0,0 +1,19 @@
+/* Copyright (c) 2013 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.
+ */
+
+/**
+ * @fileoverview
+ * Definitions for some browser-supplied globals that are not defined in a
+ * gtest environment.
+ */
+
+var XMLHttpRequest = function() {};
+
+var window = {
+  addEventListener: function() {},
+  location: {
+    pathname: ''
+  }
+};