byte order. This is needed because the unix gtk image munging code expects
the image data to be in RGB format.
The ConvertRGBToRGB24 conversion is obviously a waste of time on unix and
probably mac.
Unfortunately, the alternative seems to require significant IMGLIB
work. Simply seeting to ic->converter to NULL for the 24 bit case
did not work as expected.
The correct fix might be to not do any conversion if the image data
is already in the format expected on the nsIImage end.
git-svn-id: svn://10.0.0.236/trunk@25205 18797224-902f-48f8-a5cc-f745e15eee43