Remove duplicated headers from platform/

Source/platform/CrossThreadCopier.cpp

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * 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
@@ skipping 18 matching lines @@
  */
 
 #include "config.h"
 
 #include "platform/CrossThreadCopier.h"
 
 #include "platform/network/ResourceError.h"
 #include "platform/network/ResourceRequest.h"
 #include "platform/network/ResourceResponse.h"
 #include "weborigin/KURL.h"
-#include "wtf/Assertions.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 CrossThreadCopierBase<false, false, KURL>::Type CrossThreadCopierBase<false, false, KURL>::copy(const KURL& url)
 {
     return url.copy();
 }
 
 CrossThreadCopierBase<false, false, String>::Type CrossThreadCopierBase<false, false, String>::copy(const String& str)
@@ skipping 74 matching lines @@
                PassOwnPtrTest);
 
 // Verify that PassOwnPtr does not get passed through.
 COMPILE_ASSERT((WTF::IsSameType<
                   int,
                   CrossThreadCopier<OwnPtr<float> >::Type
                   >::value),
                OwnPtrTest);
 
 } // namespace WebCore