nsPresContext::ClearStyleDataAndReflow();
return mShell->ReconstructStyleData();
nsPresContext::ThemeChanged(){  // Tell the theme that it changed, so it can flush any handles to stale theme  // data.  if (mTheme)    mTheme->ThemeChanged();  // Clear all cached nsILookAndFeel colors.  if (mLookAndFeel)    mLookAndFeel->LookAndFeelChanged();  // We have to clear style data because the assumption of style rule  // immutability has been violated since any style rule that uses  // system colors or fonts (and probably -moz-appearance as well) has  // changed.  nsPresContext::ClearStyleDataAndReflow();}