Use a forward declaration of RSAPrivateKey in crypto/signature_creator.h.

crypto/signature_creator_win.cc

 // Copyright (c) 2011 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.
 
 #include "crypto/signature_creator.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "crypto/rsa_private_key.h"
 
 namespace crypto {
 
 // static
 SignatureCreator* SignatureCreator::Create(RSAPrivateKey* key) {
   scoped_ptr<SignatureCreator> result(new SignatureCreator);
   result->key_ = key;
 
   if (!CryptCreateHash(key->provider(), CALG_SHA1, 0, 0,
                        result->hash_object_.receive())) {
@@ skipping 32 matching lines @@
   }
 
   temp.resize(signature_length);
   for (size_t i = temp.size(); i > 0; --i)
     signature->push_back(temp[i - 1]);
 
   return true;
 }
 
 }  // namespace crypto