Introduce cc StructTraits unit tests

cc/test/run_all_unittests.cc

 // Copyright (c) 2012 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.
 
 #include "base/bind.h"
 #include "base/test/launcher/unit_test_launcher.h"
 #include "cc/test/cc_test_suite.h"
+#include "mojo/edk/embedder/embedder.h"
 
 int main(int argc, char** argv) {
   cc::CCTestSuite test_suite(argc, argv);
 
+  mojo::edk::Init();
+
   return base::LaunchUnitTests(
       argc,
       argv,
       base::Bind(&cc::CCTestSuite::Run, base::Unretained(&test_suite)));
 }