With this change, the CMake build, which does not use DEPS to sync
external projects, is able to build and use the same version of libpng
that is used in other builds.
This will allow all platforms (including Google3 CMake build) to test on
the same version of libpng, so we do not need to make SkPngCodec support
all versions of libpng.
- Update CMakeLists.txt to use the checked in libpng.
- Check in libpng version 1.6.22rc01
- Update README.google
- Replace our old LICENSE file with the latest one from libpng
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2033063003
CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot,Build-Mac-Clang-x86_64-Release-CMake-Trybot
Review-Url: https://codereview.chromium.org/2033063003
