Unnecessary call to HistoryItem::targetItem in HistoryController::pushState createTreeItem is called with m_frame, and createTreeItem sets isTargetItem to true if the Frame passed to it is equal to m_frame. so calling targetItem on the result returned from createTreeItem(m_frame,...) is unnecessary.
Created attachment 47142 [details] v1 patch
Landed as http://trac.webkit.org/changeset/53650