GitLab

This is done as part of splitting IDL and renaming ControlService
to UpdateServiceInternal.

This change:
* removes a sequence checker on the object destructor
* replaces a thread checker with a sequence checker
* replaces a couple of posted callbacks with direct Run().
* renames com_task_runner to STA_task_runner to
make it clear it is the task runner running the COM code in the
COM apartment and not some other task runner, and for acronym
capitalization
* uses a SingleThreadTaskRunner instead of a SequencedTaskRunner.

The intention is to declutter the code a little and possibly
simplify the sequence checker management on destruction.

Bug: 1140562, 1143011
Change-Id: I6db022483c72d340da3cd053e6a900db4c5702ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2510912Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Commit-Queue: Sorin Jianu <sorin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822822}