Allow WebGL readback for Mesa llvmpipe driver
Currently llvmpipe driver from Mesa is black listed.
It is fast and stable enough to allow using the gpu
process. But only enable WebGL, other features still won't
use the gpu process. For example the 2D Compositing Skia is
faster than gpu compositing on software GL driver.
BUG=571899
R=kbr@chromium.org, piman@chromium.org, zmo@chromium.org
TEST= GALLIUM_DRIVER=llvmpipe LIBGL_ALWAYS_SOFTWARE=1 chrome
CQ_INCLUDE_TRYBOTS=tryserver.chromium.win:win_optional_gpu_tests_rel
Review URL: https://codereview.chromium.org/1548893004
Cr-Commit-Position: refs/heads/master@{#389879}
2 files changed
