Remove use of WebCrypto digestSynchronous in Blink.

Source/platform/Crypto.cpp

 // 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 "config.h"
 #include "platform/Crypto.h"
 
 #include "public/platform/Platform.h"
 #include "public/platform/WebArrayBuffer.h"
 #include "public/platform/WebCrypto.h"
@@ skipping 13 matching lines @@
     case HashAlgorithmSha384:
         return blink::WebCryptoAlgorithmIdSha384;
     case HashAlgorithmSha512:
         return blink::WebCryptoAlgorithmIdSha512;
     };
 
     ASSERT_NOT_REACHED();
     return blink::WebCryptoAlgorithmIdSha256;
 }
 
-void computeDigest(HashAlgorithm algorithm, const char* digestable, size_t length, DigestValue& digestResult)
+bool computeDigest(HashAlgorithm algorithm, const char* digestable, size_t length, DigestValue& digestResult)
 {
     blink::WebCryptoAlgorithmId algorithmId = toWebCryptoAlgorithmId(algorithm);
     blink::WebCrypto* crypto = blink::Platform::current()->crypto();
-    blink::WebArrayBuffer result;
+    unsigned char* result;
+    unsigned resultSize;
 
     ASSERT(crypto);
 
-    crypto->digestSynchronous(algorithmId, reinterpret_cast<const unsigned char*>(digestable), length, result);
+    OwnPtr<blink::WebCryptoDigestor> digestor = adoptPtr(crypto->createDigestor(algorithmId));
+    if (!digestor.get() || !digestor->consume(reinterpret_cast<const unsigned char*>(digestable), length) || !digestor->finish(result, resultSize))
+        return false;
 
-    ASSERT(!result.isNull());
-
-    digestResult.append(static_cast<uint8_t*>(result.data()), result.byteLength());
+    digestResult.append(static_cast<uint8_t*>(result), resultSize);
+    return true;
 }
 
 PassOwnPtr<blink::WebCryptoDigestor> createDigestor(HashAlgorithm algorithm)
 {
     return adoptPtr(blink::Platform::current()->crypto()->createDigestor(toWebCryptoAlgorithmId(algorithm)));
 }
 
 void finishDigestor(blink::WebCryptoDigestor* digestor, DigestValue& digestResult)
 {
     unsigned char* result = 0;
     unsigned resultSize = 0;
 
     if (!digestor->finish(result, resultSize))
         return;
 
     ASSERT(result);
 
     digestResult.append(static_cast<uint8_t*>(result), resultSize);
 }
 
 } // namespace WebCore