chromeos: If there is capture, send to owner or do nothing

For top-levels, if there is capture then send to the client (if the client
requested capture), otherwise do nothing (local environment handles it). For
non-top levels if there is capture then always use the capture-owner.

BUG=837692
TEST=covered by tests

Change-Id: I38914a49866c49e4827b47b8748e2e6ebb143679
Reviewed-on: https://chromium-review.googlesource.com/1077968
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562956}
4 files changed