mFrameState = aPresShell->GetDocument()->GetLayoutHistoryState();
nsFrameConstructorState::nsFrameConstructorState(nsIPresShell*          aPresShell,                                                 nsIFrame*              aFixedContainingBlock,                                                 nsIFrame*              aAbsoluteContainingBlock,                                                 nsIFrame*              aFloatContainingBlock,                                                 nsILayoutHistoryState* aHistoryState)  : mPresContext(aPresShell->GetPresContext()),    mPresShell(aPresShell),    mFrameManager(aPresShell->FrameManager()),    mFixedItems(aFixedContainingBlock),    mAbsoluteItems(aAbsoluteContainingBlock),    mFloatedItems(aFloatContainingBlock),    mFirstLetterStyle(PR_FALSE),    mFirstLineStyle(PR_FALSE),    mFrameState(aHistoryState),    mPseudoFrames(),    mAnonymousCreator(nsnull),    mInsertionContent(nsnull),    mCreatorIsBlock(PR_FALSE){}