Revert 20962 "Break cyclic reference between utils and platform."

src/platform.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 30 matching lines @@
 // implementation and the overhead of virtual methods for performance
 // sensitive like mutex locking/unlocking.
 
 #ifndef V8_PLATFORM_H_
 #define V8_PLATFORM_H_
 
 #include <stdarg.h>
 
 #include "platform/mutex.h"
 #include "platform/semaphore.h"
-#include "vector.h"
+#include "utils.h"
 #include "v8globals.h"
 
 #ifdef __sun
 # ifndef signbit
 namespace std {
 int signbit(double x);
 }
 # endif
 #endif
 
@@ skipping 555 matching lines @@
   char name_[kMaxThreadNameLength];
   int stack_size_;
   Semaphore* start_semaphore_;
 
   DISALLOW_COPY_AND_ASSIGN(Thread);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_PLATFORM_H_