GitLab

ConditionVariable by default emits a trace event from Wait().
Message pump like code needs to explicitly disable this to avoid
emitting trace events while sleeping that make the thread incorrectly
look busy.

R=pwnall@chromium.org

Bug: 899897
Change-Id: I5c7078db3e4889ae3e946e045a4e626fcd7ee8b8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2090505
Commit-Queue: Gabriel Charette <gab@chromium.org>
Auto-Submit: Gabriel Charette <gab@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747924}