GitLab

Restrict extended-drag extension to OS_CHROMEOS as it depends directly
into some ash components, which are not included in cast product builds.

R=oshima@chromium.org, spang@chromium.org

Bug: 1099418, 1146150
Change-Id: I5269825917ce9343e438aaabb9b11f560187ac0e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2521694
Commit-Queue: Nick Yamane <nickdiego@igalia.com>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824949}