GitLab

GetMaxConcurrency() is given the active worker_count. The main thread shouldn't
be counted when it returns, otherwise causing infinite job.

Bug: 1114823
Change-Id: I4954559992a8e17a92dbbbc9e3bce152563d1235
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2355297Reviewed-by: François Doray <fdoray@chromium.org>
Commit-Queue: François Doray <fdoray@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799094}