Make header include guards great again

runtime/vm/message_handler.h

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-#ifndef VM_MESSAGE_HANDLER_H_
-#define VM_MESSAGE_HANDLER_H_
+#ifndef RUNTIME_VM_MESSAGE_HANDLER_H_
+#define RUNTIME_VM_MESSAGE_HANDLER_H_
 
 #include "vm/isolate.h"
 #include "vm/lockers.h"
 #include "vm/message.h"
 #include "vm/os_thread.h"
 #include "vm/thread_pool.h"
 
 namespace dart {
 
 // A MessageHandler is an entity capable of accepting messages.
@@ skipping 234 matching lines @@
   ThreadPool::Task* task_;
   StartCallback start_callback_;
   EndCallback end_callback_;
   CallbackData callback_data_;
 
   DISALLOW_COPY_AND_ASSIGN(MessageHandler);
 };
 
 }  // namespace dart
 
-#endif  // VM_MESSAGE_HANDLER_H_
+#endif  // RUNTIME_VM_MESSAGE_HANDLER_H_