Build WTF as dll in component build

Source/wtf/ThreadingWin.cpp

 /*
  * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile, Inc. All rights reserved.
  *
  * 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
@@ skipping 149 matching lines @@
 }
 
 static Mutex& threadMapMutex()
 {
     static Mutex mutex;
     return mutex;
 }
 
 void initializeThreading()
 {
-    if (atomicallyInitializedStaticMutex)
-        return;
+    // This should only be called once.
+    ASSERT(!atomicallyInitializedStaticMutex);
 
     WTF::double_conversion::initialize();
     // StringImpl::empty() does not construct its static string in a threadsafe fashion,
     // so ensure it has been initialized from here.
     StringImpl::empty();
     atomicallyInitializedStaticMutex = new Mutex;
     threadMapMutex();
     initializeRandomNumberGenerator();
     wtfThreadData();
     s_dtoaP5Mutex = new Mutex;
@@ skipping 321 matching lines @@
     // Time is too far in the future (and would overflow unsigned long) - wait forever.
     if (absoluteTime - currentTime > static_cast<double>(INT_MAX) / 1000.0)
         return INFINITE;
 
     return static_cast<DWORD>((absoluteTime - currentTime) * 1000.0);
 }
 
 } // namespace WTF
 
 #endif // OS(WINDOWS)