::GetTextExtentPoint32A(aDC, buffer.get(), aLength, &size); size.cx -= mOverhangCorrection;
::GetTextExtentPoint32A(aDC, str, len, &size);
nsFontSubset::GetWidth(HDC aDC, const PRUnichar* aString, PRUint32 aLength){  nsAutoCharBuffer buffer;  Convert(aString, aLength, buffer, &aLength);  if (aLength) {    SIZE size;    ::GetTextExtentPoint32A(aDC, buffer.get(), aLength, &size);    size.cx -= mOverhangCorrection;    return size.cx;  }  return 0;}