Fix OWNERS.

struct_traits files need security owner review.
Add OWNERS file for missing ones (volume_mounter, timer).
Also, renamed _traits to _struct_traits for consistency.

BUG=None
TEST=Build.

Change-Id: Ic9e1c75e63cfd0a3c34a3ef5bc0f60f840285912
Reviewed-on: https://chromium-review.googlesource.com/1074912
Reviewed-by: Luis Hector Chavez <lhchavez@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562424}
10 files changed