[webcrypto] Add JWK symmetric key AES-KW unwrap for NSS.

content/child/webcrypto/platform_crypto_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/platform_crypto.h"
 
 #include <vector>
 #include <openssl/aes.h>
 #include <openssl/evp.h>
 #include <openssl/hmac.h>
@@ skipping 385 matching lines @@
 Status UnwrapSymKeyAesKw(const CryptoData& wrapped_key_data,
                          SymKey* wrapping_key,
                          const blink::WebCryptoAlgorithm& algorithm,
                          bool extractable,
                          blink::WebCryptoKeyUsageMask usage_mask,
                          blink::WebCryptoKey* key) {
   // TODO(eroman): http://crbug.com/267888
   return Status::ErrorUnsupported();
 }
 
+Status DecryptAesKw(SymKey* key,
+                    const CryptoData& data,
+                    blink::WebArrayBuffer* buffer) {
+  // TODO(eroman): http://crbug.com/267888
+  return Status::ErrorUnsupported();
+}
+
 Status WrapSymKeyRsaEs(PublicKey* wrapping_key,
                        SymKey* key,
                        blink::WebArrayBuffer* buffer) {
   // TODO(eroman): http://crbug.com/267888
   return Status::ErrorUnsupported();
 }
 
 Status UnwrapSymKeyRsaEs(const CryptoData& wrapped_key_data,
                          PrivateKey* wrapping_key,
                          const blink::WebCryptoAlgorithm& algorithm,
                          bool extractable,
                          blink::WebCryptoKeyUsageMask usage_mask,
                          blink::WebCryptoKey* key) {
   // TODO(eroman): http://crbug.com/267888
   return Status::ErrorUnsupported();
 }
 
 }  // namespace platform
 
 }  // namespace webcrypto
 
 }  // namespace content