[webcrypto] Match the error handling defined by the spec.

Source/core/platform/chromium/support/WebCrypto.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 25 matching lines @@
 #include <string.h>
 
 namespace blink {
 
 void WebCryptoResult::completeWithError()
 {
     m_impl->completeWithError();
     reset();
 }
 
+void WebCryptoResult::completeWithError(const WebString& errorDetails)
+{
+    // FIXME: The error details are being temporarily discarded. Once the
+    // Chromium side has been updated to emit error details, this should be
+    // enabled and the layouttests rebaselined.
+    m_impl->completeWithError(/*errorDetails*/);
+    reset();
+}
+
 void WebCryptoResult::completeWithBuffer(const WebArrayBuffer& buffer)
 {
     RELEASE_ASSERT(!buffer.isNull());
     m_impl->completeWithBuffer(buffer);
     reset();
 }
 
 void WebCryptoResult::completeWithBuffer(const void* bytes, unsigned bytesSize)
 {
     WebArrayBuffer buffer = blink::WebArrayBuffer::create(bytesSize, 1);
@@ skipping 33 matching lines @@
 {
     m_impl.reset();
 }
 
 void WebCryptoResult::assign(const WebCryptoResult& o)
 {
     m_impl = o.m_impl;
 }
 
 } // namespace blink