chromeos-chrome: Introduce USE=xkbcommon

We'll use this flag to pull in keyboard layout support using
libxkbcommon under freon/ozone.

BUG=chromium:362698
TEST=emerge-link_freon libxkbcommon

Change-Id: Ia03664ae20a12e60d65527b8885b128d8e8b47a7
Reviewed-on: https://chromium-review.googlesource.com/213144
Reviewed-by: Kevin Schoedel <kpschoedel@chromium.org>
Reviewed-by: Shu Chen <shuchen@chromium.org>
Tested-by: Michael Spang <spang@chromium.org>
Commit-Queue: Michael Spang <spang@chromium.org>
1 file changed