chromeos: only register for first-surface-activation if necessary

This is only necessary when running in tests.

BUG=none
TEST=covered by tests

Change-Id: Ifa5aeace0ee9623e9392b2fb0912e1c2be7d6005
Reviewed-on: https://chromium-review.googlesource.com/c/1476032
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Saman Sami <samans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#632840}
1 file changed