func:  RestyleManager::DebugVerifyStyleTree(nsIFrame* aFrame) if ( aFrame )  nsStyleContext * context = aFrame -> StyleContext ( ) ; nsStyleContext * parentContext = context -> GetParent ( ) ; VerifyStyleTree ( mPresContext , aFrame , parentContext ); static VerifyStyleTree(nsPresContext* aPresContext, nsIFrame* nsStyleContext* aParentContext) nsStyleContext * context = aFrame -> StyleContext ( ) ; VerifyContextParent ( aPresContext , aFrame , context , nullptr ); static VerifyContextParent(nsPresContext* aPresContext, nsIFrame* nsStyleContext* aContext, nsStyleContext* aParentContext) if ( ! aContext )  aContext = aFrame -> StyleContext ( ); if ( ! aParentContext )  nsIFrame * providerFrame = aFrame -> GetParentStyleContextFrame ( ) ; if ( providerFrame )  aParentContext = providerFrame -> StyleContext ( ); nsStyleContext * actualParentContext = aContext -> GetParent ( ) ; if ( aParentContext )  if ( aParentContext != actualParentContext )  if ( aContext == aParentContext )  fputs ( "\n" , stdout ); 