Resolve a TSAN race in CertVerifyProc

Resolve a TSAN race in CertVerifyProc

TSAN gets unhappy because MultiThreadedCertVerifier abandons its
worker threads (because they may be blocked on OS APIs) when
shutting down tests, which interferes with ScopedFeatureList
shutdown code in //net.

This simply moves the check from being on the worker thread
when it's running, to being on the main thread when the
CertVerifyProc is constructed.

BUG=663850
Committed: https://crrev.com/9d3cd28a62874bbdc27be9134dd6fe53f6b8cd10
Cr-Commit-Position: refs/heads/master@{#431164}

[Ryan Sleevi, 2016-11-10 00:29:50]

rsleevi@chromium.org changed reviewers:
+ davidben@chromium.org

[Ryan Sleevi, 2016-11-10 00:29:51]

Went for the lazy fix - when we remove legacy mode we can remove this.

[davidben, 2016-11-10 00:48:38]

lgtm

[Ryan Sleevi, 2016-11-10 01:27:47]

The CQ bit was checked by rsleevi@chromium.org

[commit-bot: I haz the power, 2016-11-10 01:28:15]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-10 03:22:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-10 03:24:52]

Description was changed from

==========
Resolve a TSAN race in CertVerifyProc

TSAN gets unhappy because MultiThreadedCertVerifier abandons its
worker threads (because they may be blocked on OS APIs) when
shutting down tests, which interferes with ScopedFeatureList
shutdown code in //net.

This simply moves the check from being on the worker thread
when it's running, to being on the main thread when the
CertVerifyProc is constructed.

BUG=663850
==========

to

==========
Resolve a TSAN race in CertVerifyProc

TSAN gets unhappy because MultiThreadedCertVerifier abandons its
worker threads (because they may be blocked on OS APIs) when
shutting down tests, which interferes with ScopedFeatureList
shutdown code in //net.

This simply moves the check from being on the worker thread
when it's running, to being on the main thread when the
CertVerifyProc is constructed.

BUG=663850

Committed: https://crrev.com/9d3cd28a62874bbdc27be9134dd6fe53f6b8cd10
Cr-Commit-Position: refs/heads/master@{#431164}
==========

[commit-bot: I haz the power, 2016-11-10 03:24:53]

Patchset 1 (id:??) landed as
https://crrev.com/9d3cd28a62874bbdc27be9134dd6fe53f6b8cd10
Cr-Commit-Position: refs/heads/master@{#431164}