RAPTOR_STOPWATCH_DEBUGTRACE(("Stop: nsHTMLContentSink::OpenHead()\n"));
HTMLContentSink::OpenHead(const nsIParserNode& aNode){  NS_START_STOPWATCH(mWatch)  SINK_TRACE_NODE(SINK_TRACE_CALLS,                  "HTMLContentSink::OpenHead", aNode, this);  nsresult rv = NS_OK;  if (nsnull == mHeadContext) {    mHeadContext = new SinkContext(this);    if (nsnull == mHeadContext) {      NS_STOP_STOPWATCH(mWatch)      return NS_ERROR_OUT_OF_MEMORY;    }    mHeadContext->SetPreAppend(PR_TRUE);    rv = mHeadContext->Begin(eHTMLTag_head, mHead);    if (NS_OK != rv) {      NS_STOP_STOPWATCH(mWatch)      return rv;    }  }  mContextStack.AppendElement(mCurrentContext);  mCurrentContext = mHeadContext;  if (nsnull != mHead) {    nsIScriptContextOwner* sco = mDocument->GetScriptContextOwner();    rv = AddAttributes(aNode, mHead, sco);    NS_IF_RELEASE(sco);  }