Remove #pragma once from crypto

crypto/ec_signature_creator_impl.h

 // Copyright (c) 2012 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.
 
 #ifndef CRYPTO_EC_SIGNATURE_CREATOR_IMPL_H_
 #define CRYPTO_EC_SIGNATURE_CREATOR_IMPL_H_
-#pragma once
 
 #include "base/compiler_specific.h"
 #include "crypto/ec_signature_creator.h"
 
 namespace crypto {
 
 class ECSignatureCreatorImpl : public ECSignatureCreator {
  public:
   explicit ECSignatureCreatorImpl(ECPrivateKey* key);
   virtual ~ECSignatureCreatorImpl();
 
   virtual bool Sign(const uint8* data,
                     int data_len,
                     std::vector<uint8>* signature) OVERRIDE;
 
  private:
   ECPrivateKey* key_;
 
   DISALLOW_COPY_AND_ASSIGN(ECSignatureCreatorImpl);
 };
 
 }  // namespace crypto
 
 #endif  // CRYPTO_EC_SIGNATURE_CREATOR_IMPL_H_