Add content implementation of digestSynchcronous.

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/logging.h"
 #include "content/renderer/webcrypto/crypto_data.h"
 #include "content/renderer/webcrypto/shared_crypto.h"
 #include "content/renderer/webcrypto/webcrypto_util.h"
@@ skipping 176 matching lines @@
       key,
       webcrypto::CryptoData(signature, signature_size),
       webcrypto::CryptoData(data, data_size),
       &signature_match);
   if (status.IsError())
     CompleteWithError(status, &result);
   else
     result.completeWithBoolean(signature_match);
 }
 
+// This method synchronously computes a digest for the given data, returning

[eroman, 2014/02/21 23:11:20]

Can you move this comment to the header file?

[jww, 2014/02/21 23:23:34]

Done.

+// |true| if successful and |false| otherwise. This relies on the
+// webcrypto::Digest() implementation being synchronous as well, so if that ever

[eroman, 2014/02/21 23:11:20]

Please remove this comment, I think the function signatures already explain
that.

[jww, 2014/02/21 23:23:34]

Done.

+// changes, this method will also need to be modified.
+bool WebCryptoImpl::digestSynchronous(
+    const blink::WebCryptoAlgorithmId algorithm_id,

[eroman, 2014/02/21 23:11:20]

in the header this is called "algorithm". Please use a consistent name
throughout.

[jww, 2014/02/21 23:23:34]

Done.

+    const unsigned char* data,
+    unsigned int data_size,
+    blink::WebArrayBuffer& result) {

[eroman, 2014/02/21 23:11:20]

did you run "git cl format". If not please do, trying to keep these files
formatted by that tool.

[jww, 2014/02/21 23:23:34]

Yup, I ran git-cl format over this. In fact, the wacky bit below was the result
of that. If you have a preferred formatting for this, I'm happy to format it as
such, as this is objectively pretty ugly :-)

+  blink::WebCryptoAlgorithm algorithm =
+      blink::WebCryptoAlgorithm::adoptParamsAndCreate(algorithm_id, NULL);
+  return (webcrypto::Digest(
+              algorithm, webcrypto::CryptoData(data, data_size), &result))
+      .IsSuccess();
+}
+
 }  // namespace content