GitLab

Restrict the admissible set of clock IDs to just CLOCK_MONOTONIC,
CLOCK_PROCESS_CPUTIME_ID, CLOCK_REALTIME, and CLOCK_THREAD_CPUTIME_ID
(i.e., the same clocks allowed in regular NaCl).  In particular, we do
not allow arbitrary per-process CPU clocks, which can leak information
about the state of other non-SFI processes.

BUG=374479
TBR=cpu@chromium.org

Review URL: https://codereview.chromium.org/286363003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@271859 0039d316-1c4b-4281-b951-d872f2087c98