NS_ADD_SVGVALUE_OBSERVER(mStrokeGradient);
NS_REMOVE_SVGVALUE_OBSERVER(mStrokeGradient);
nsSVGGlyphFrame::DidSetStyleContext(nsPresContext* aPresContext){  // One of the styles that might have been changed are the urls that  // point to gradients, etc.  Drop our cached values to those  if (mFillGradient) {    NS_ADD_SVGVALUE_OBSERVER(mFillGradient);    mFillGradient = nsnull;  }  if (mStrokeGradient) {    NS_ADD_SVGVALUE_OBSERVER(mStrokeGradient);    mStrokeGradient = nsnull;  }  return CharacterDataChanged(aPresContext, nsnull, PR_FALSE);}