[webcrypto] Implement AES-CTR using BoringSSL.

content/child/webcrypto/nss/util_nss.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/nss/util_nss.h"
 
 #include "base/lazy_instance.h"
 #include "content/child/webcrypto/crypto_data.h"
+#include "content/child/webcrypto/platform_crypto.h"
 #include "crypto/nss_util.h"
 #include "crypto/scoped_nss_types.h"
 
 #if defined(USE_NSS)
 #include <dlfcn.h>
 #include <secoid.h>
 #endif
 
 namespace content {
 
@@ skipping 53 matching lines @@
     internal_slot_does_oaep_ =
         !!PK11_DoesMechanism(slot.get(), CKM_RSA_PKCS_OAEP);
   }
 #endif
 }
 
 void PlatformInit() {
   crypto::EnsureNSSInit();
 }
 
+AlgorithmImplementation* CreatePlatformAesCtrImplementation() {
+  // TODO(eroman): http://crbug.com/399084
+  return NULL;
+}
+
 }  // namespace webcrypto
 
 }  // namespace content