Add media router common classes and unittests.

chrome/browser/media/router/media_router.gyp

Index: chrome/browser/media/router/media_router.gyp
diff --git a/chrome/browser/media/router/media_router.gyp b/chrome/browser/media/router/media_router.gyp
new file mode 100644
index 0000000000000000000000000000000000000000..6b9756c711dc00c7591f3bd2b3b5b5157a62c16b
--- /dev/null
+++ b/chrome/browser/media/router/media_router.gyp
@@ -0,0 +1,33 @@
+# 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.
+
+{
+  'targets': [
+    {
+      'target_name': 'media_router',
+      'type': 'static_library',
+      'include_dirs': [
+        '<(DEPTH)',
+      ],
+      'dependencies': [
+        '<(DEPTH)/base/base.gyp:base',
+        '<(DEPTH)/url/url.gyp:url_lib',
+      ],
+      'sources': [
+        'common.h',
+        'media_route.cc',
+        'media_route.h',
+        'media_route_id.h',
+        'media_sink.cc',
+        'media_sink.h',
+        'media_source.cc',
+        'media_source.h',
+        'media_source_helper.cc',
+        'media_source_helper.h',
+        'route_id_manager.cc',
+        'route_id_manager.h',
+      ],
+    },
+  ],
+}