nsresult result = mCurrentEventContent->GetDocument(*getter_AddRefs(doc));
nsresult result = mCurrentEventContent->GetDocument(getter_AddRefs(doc));
PresShell::GetCurrentEventFrame(){  if (!mCurrentEventFrame && mCurrentEventContent) {    // Make sure the content still has a document reference. If not,    // then we assume it is no longer in the content tree and the    // frame shouldn't get an event, nor should we even assume its    // safe to try and find the frame.    nsCOMPtr<nsIDocument> doc;    nsresult result = mCurrentEventContent->GetDocument(*getter_AddRefs(doc));    if (NS_SUCCEEDED(result) && doc) {      GetPrimaryFrameFor(mCurrentEventContent, &mCurrentEventFrame);    }  }  return mCurrentEventFrame;}