[webcrypto] Implement AES-CTR using BoringSSL.

content/child/webcrypto/platform_crypto.h

 // 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.
 
 #ifndef CONTENT_CHILD_WEBCRYPTO_PLATFORM_CRYPTO_H_
 #define CONTENT_CHILD_WEBCRYPTO_PLATFORM_CRYPTO_H_
 
 #include <stdint.h>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "third_party/WebKit/public/platform/WebCrypto.h"
 
 // The definitions for these methods lives in either nss/ or openssl/
 namespace content {
 
 namespace webcrypto {
 
 class AlgorithmImplementation;
 
 void PlatformInit();
 
 scoped_ptr<blink::WebCryptoDigestor> CreatePlatformDigestor(
     blink::WebCryptoAlgorithmId algorithm);
 
 AlgorithmImplementation* CreatePlatformShaImplementation();
 AlgorithmImplementation* CreatePlatformAesCbcImplementation();
+AlgorithmImplementation* CreatePlatformAesCtrImplementation();
 AlgorithmImplementation* CreatePlatformAesGcmImplementation();
 AlgorithmImplementation* CreatePlatformAesKwImplementation();
 AlgorithmImplementation* CreatePlatformHmacImplementation();
 AlgorithmImplementation* CreatePlatformRsaOaepImplementation();
 AlgorithmImplementation* CreatePlatformRsaSsaImplementation();
 
 bool PlatformSerializeKeyForClone(const blink::WebCryptoKey& key,
                                   blink::WebVector<uint8_t>* key_data);
 
 }  // namespace webcrypto
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_WEBCRYPTO_PLATFORM_CRYPTO_H_