add README.chromium

  ¯\_(ツ)_/¯

Bug: chromium:839924

Change-Id: I0f97d121bcbb1c0491bdf043361b6815edb61683
Reviewed-on: https://skia-review.googlesource.com/126701
Auto-Submit: Mike Klein <mtklein@chromium.org>
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
1 file changed