[webcrypto] Expose crypto.subtle to web workers.

Source/modules/crypto/Crypto.cpp

 /*
  * Copyright (C) 2011 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 40 matching lines @@
         || type == ArrayBufferView::TypeUint32;
 }
 
 }
 
 Crypto::Crypto()
 {
     ScriptWrappable::init(this);
 }
 
-// Note: This implementation must be thread-safe, as it is used by workers.
 void Crypto::getRandomValues(ArrayBufferView* array, ExceptionState& exceptionState)
 {
     if (!array) {
         exceptionState.throwDOMException(TypeMismatchError, "The provided ArrayBufferView is null.");
         return;
     }
     if (!isIntegerArray(array)) {
         exceptionState.throwDOMException(TypeMismatchError, String::format("The provided ArrayBufferView is of type '%s', which is not an integer array type.", array->typeName()));
         return;
     }
@@ skipping 10 matching lines @@
         m_subtleCrypto = SubtleCrypto::create();
     return m_subtleCrypto.get();
 }
 
 void Crypto::trace(Visitor* visitor)
 {
     visitor->trace(m_subtleCrypto);
 }
 
 }