Add media router common classes and unittests.

chrome/browser/media/router/media_router_tests.gypi

Index: chrome/browser/media/router/media_router_tests.gypi
diff --git a/chrome/browser/media/router/media_router_tests.gypi b/chrome/browser/media/router/media_router_tests.gypi
new file mode 100644
index 0000000000000000000000000000000000000000..1c748321c22f4db7392bb8df57d4a809c13ee742
--- /dev/null
+++ b/chrome/browser/media/router/media_router_tests.gypi
@@ -0,0 +1,13 @@
+# Copyright 2015 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.
+
+{
+  'sources': [
+    'media_route_unittest.cc',
+    'media_sink_unittest.cc',
+    'media_source_helper_unittest.cc',
+    'media_source_unittest.cc',
+    'route_id_manager_unittest.cc',
+  ],
+}