Disable COM Initialization on SchedulerWorkers When COM_INIT_CHECK_HOOK_ENABLED()

This change will allow for the detection of tasks running in
TaskScheduler that fail to post their task in a COM STA Task Runner
instead.

BUG=706512
TBR=gab@chromium.org
Previously Reviewed at https://chromium-review.googlesource.com/c/549223/

Review-Url: https://codereview.chromium.org/2978253002
Cr-Original-Commit-Position: refs/heads/master@{#487625}
Committed: https://chromium.googlesource.com/chromium/src/+/122a24f59d90a1b225e00b3ab6c9fd37fd365b8f
Review-Url: https://codereview.chromium.org/2978253002
Cr-Commit-Position: refs/heads/master@{#488327}