Revert "Move mojo edk into mojo/edk"

mojo/system/test_utils.h

 // Copyright 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.
 
-#ifndef MOJO_EDK_SYSTEM_TEST_UTILS_H_
-#define MOJO_EDK_SYSTEM_TEST_UTILS_H_
+#ifndef MOJO_SYSTEM_TEST_UTILS_H_
+#define MOJO_SYSTEM_TEST_UTILS_H_
 
 #include <stdint.h>
 
 #include "base/callback_forward.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/task_runner.h"
 #include "base/threading/thread.h"
 #include "base/time/time.h"
@@ skipping 34 matching lines @@
  private:
   base::TimeTicks start_time_;
 
   DISALLOW_COPY_AND_ASSIGN(Stopwatch);
 };
 
 }  // namespace test
 }  // namespace system
 }  // namespace mojo
 
-#endif  // MOJO_EDK_SYSTEM_TEST_UTILS_H_
+#endif  // MOJO_SYSTEM_TEST_UTILS_H_