[webcrypto] Add decrypt() for AES-CBC.

content/renderer/webcrypto/webcrypto_impl.cc

 // Copyright (c) 2013 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/renderer/webcrypto/webcrypto_impl.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "third_party/WebKit/public/platform/WebArrayBuffer.h"
 #include "third_party/WebKit/public/platform/WebCryptoAlgorithm.h"
 #include "third_party/WebKit/public/platform/WebCryptoKey.h"
@@ skipping 11 matching lines @@
     unsigned data_size,
     WebKit::WebCryptoResult result) {
   WebKit::WebArrayBuffer buffer;
   if (!EncryptInternal(algorithm, key, data, data_size, &buffer)) {
     result.completeWithError();
   } else {
     result.completeWithBuffer(buffer);
   }
 }
 
+void WebCryptoImpl::decrypt(
+    const WebKit::WebCryptoAlgorithm& algorithm,
+    const WebKit::WebCryptoKey& key,
+    const unsigned char* data,
+    unsigned data_size,
+    WebKit::WebCryptoResult result) {
+  WebKit::WebArrayBuffer buffer;
+  if (!DecryptInternal(algorithm, key, data, data_size, &buffer)) {
+    result.completeWithError();
+  } else {
+    result.completeWithBuffer(buffer);
+  }
+}
+
 void WebCryptoImpl::digest(
     const WebKit::WebCryptoAlgorithm& algorithm,
     const unsigned char* data,
     unsigned data_size,
     WebKit::WebCryptoResult result) {
   WebKit::WebArrayBuffer buffer;
   if (!DigestInternal(algorithm, data, data_size, &buffer)) {
     result.completeWithError();
   } else {
     result.completeWithBuffer(buffer);
@@ skipping 59 matching lines @@
                                data,
                                data_size,
                                &signature_match)) {
     result.completeWithError();
   } else {
     result.completeWithBoolean(signature_match);
   }
 }
 
 }  // namespace content