It is still redefined, but to the same constant,
hence no more warning as mentioned on BUG=webp:358
Change-Id: I80a834c139d5d60cd693d468b0e2ea399729ab3e
The goal is not to replace our autotools configuration, but to
provide a minimal CMake file that can build the lib, cwebp and
dwebp.
Change-Id: I3be343bd698d118c5f00172449d232d87e868f23