Fix console messages in SRI errors.

Source/core/frame/SubresourceIntegrity.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 "core/frame/SubresourceIntegrity.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
@@ skipping 90 matching lines @@
             DigestValue convertedHashVector;
             convertedHashVector.append(reinterpret_cast<uint8_t*>(hashVector.data()), hashVector.size());
 
             if (DigestsEqual(digest, convertedHashVector)) {
                 UseCounter::count(document, UseCounter::SRIElementWithMatchingIntegrityAttribute);
                 return true;
             }
         }
     }
 
+    digest.clear();
     if (computeDigest(HashAlgorithmSha256, normalizedSource.data(), normalizedSource.length(), digest)) {
         // This message exposes the digest of the resource to the console.
         // Because this is only to the console, that's okay for now, but we
         // need to be very careful not to expose this in exceptions or
         // JavaScript, otherwise it risks exposing information about the
         // resource cross-origin.
         logErrorToConsole("Failed to find a valid digest in the 'integrity' attribute for resource '" + resourceUrl.elidedString() + "' with computed SHA-256 integrity '" + digestToString(digest) + "'. The resource has been blocked.", document);
     } else {
         logErrorToConsole("There was an error computing an integrity value for resource '" + resourceUrl.elidedString() + "'. The resource has been blocked.", document);
     }
@@ skipping 152 matching lines @@
         metadataList.append(integrityMetadata);
     }
 
     if (metadataList.size() == 0 && error)
         return IntegrityParseNoValidResult;
 
     return IntegrityParseValidResult;
 }
 
 } // namespace blink