Refactor the interface for generating keys.

content/child/webcrypto/openssl/sym_key_openssl.cc

 // Copyright 2014 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 "content/child/webcrypto/openssl/sym_key_openssl.h"
 
 #include <vector>
 #include <openssl/rand.h>
 
 #include "content/child/webcrypto/crypto_data.h"
+#include "content/child/webcrypto/generate_key_result.h"
 #include "content/child/webcrypto/openssl/key_openssl.h"
 #include "content/child/webcrypto/status.h"
 #include "crypto/openssl_util.h"
 #include "third_party/WebKit/public/platform/WebCryptoKeyAlgorithm.h"
 
 namespace content {
 
 namespace webcrypto {
 
 Status GenerateSecretKeyOpenSsl(const blink::WebCryptoKeyAlgorithm& algorithm,
                                 bool extractable,
                                 blink::WebCryptoKeyUsageMask usage_mask,
                                 unsigned keylen_bytes,
-                                blink::WebCryptoKey* key) {
+                                GenerateKeyResult* result) {
   crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
 
   std::vector<unsigned char> random_bytes(keylen_bytes, 0);
 
   if (keylen_bytes > 0) {
     if (!(RAND_bytes(&random_bytes[0], keylen_bytes)))
       return Status::OperationError();
   }
 
-  *key =
+  result->AssignSecretKey(
       blink::WebCryptoKey::create(new SymKeyOpenSsl(CryptoData(random_bytes)),
                                   blink::WebCryptoKeyTypeSecret,
                                   extractable,
                                   algorithm,
-                                  usage_mask);
+                                  usage_mask));
+
   return Status::Success();
 }
 
 Status ImportKeyRawOpenSsl(const CryptoData& key_data,
                            const blink::WebCryptoKeyAlgorithm& algorithm,
                            bool extractable,
                            blink::WebCryptoKeyUsageMask usage_mask,
                            blink::WebCryptoKey* key) {
   *key = blink::WebCryptoKey::create(new SymKeyOpenSsl(key_data),
                                      blink::WebCryptoKeyTypeSecret,
                                      extractable,
                                      algorithm,
                                      usage_mask);
   return Status::Success();
 }
 
 }  // namespace webcrypto
 
 }  // namespace content