Enable warning 4389 as an error on windows builds. This will make...

base/thread_local.h

-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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.
 
 // WARNING: Thread local storage is a bit tricky to get right.  Please make
 // sure that this is really the proper solution for what you're trying to
 // achieve.  Don't prematurely optimize, most likely you can just use a Lock.
 //
 // These classes implement a warpper around the platform's TLS storage
 // mechanism.  On construction, they will allocate a TLS slot, and free the
 // TLS slot on destruction.  No memory management (creation or destruction) is
@@ skipping 40 matching lines @@
 
 #if defined(OS_POSIX)
 #include <pthread.h>
 #endif
 
 namespace base {
 
 // Helper functions that abstract the cross-platform APIs.  Do not use directly.
 struct ThreadLocalPlatform {
 #if defined(OS_WIN)
-  typedef int SlotType;
+  typedef unsigned long SlotType;
 #elif defined(OS_POSIX)
   typedef pthread_key_t SlotType;
 #endif
 
   static void AllocateSlot(SlotType& slot);
   static void FreeSlot(SlotType& slot);
   static void* GetValueFromSlot(SlotType& slot);
   static void SetValueInSlot(SlotType& slot, void* value);
 };
 
@@ skipping 39 matching lines @@
 
  private:
   ThreadLocalPointer<void> tlp_;
 
   DISALLOW_COPY_AND_ASSIGN(ThreadLocalBoolean);
 };
 
 }  // namespace base
 
 #endif  // BASE_THREAD_LOCAL_H_