Remove the USE(OS_RANDOMNESS) guard.

Source/wtf/RandomNumberSeed.h

 /*
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 38 matching lines @@
     // On Windows we use rand_s which initialises itself
 #elif OS(UNIX)
     // srandomdev is not guaranteed to exist on linux so we use this poor seed, this should be improved
     timeval time;
     gettimeofday(&time, 0);
     srandom(static_cast<unsigned>(time.tv_usec * getpid()));
 #else
     srand(static_cast<unsigned>(time(0)));
 #endif
 
-#if !USE(OS_RANDOMNESS)
-    uint64_t seed = static_cast<uint64_t>(rand()) << 32 | static_cast<uint64_t>(rand());
-    Internal::initializeRandomNumber(seed);
-#endif
 }
 
 }
 
 #endif