GitLab

PrinterCapabilitiesTest currently exercises
GetSettingsOnBlockingTaskRunner() on the main thread, because blocking
is allowed on the main thread in unit tests by default.

Improve upon this by disallowing blocking on the main thread. Then
change PrinterCapabilitiesTest test cases to call
GetSettingsOnBlockingTaskRunner() on the appropriate task runner.

Change-Id: Ic97f03b38775338134f7d80de6b6aa52fc21e21b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1900772
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713251}