fix build against libpng >=1.4
According to the latest libpng manual, png_set_gray_1_2_4_to_8() is
deprecated and should be replaced with png_set_expand_gray_1_2_4_to_8()
(backported to 1.2.9).
Useful in case we ever do update libpng.
BUG=chrome-os-partner:49267
TEST=build
Change-Id: Ifbe7a670b23b8fcb7ffc7e1ebf0e6179a178271f
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/321471
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed
