Reland "SequenceManager to perform periodic housekeeping (sweep canceled tasks)"

This reverts commit 23cd26b84ec8ea9d5d6ea54a8e903c5bade93346.

The fix (https://chromium-review.googlesource.com/c/chromium/src/+/1495541) has landed so it should be safe to reland.

Original change's description:
> Revert "SequenceManager to perform periodic housekeeping (sweep canceled tasks)"
> 
> This reverts commit 606087eb105f4586e9c1af653f8005960cc664dd.
> 
> This is crashing and the speculative fix was ineffective.
> 
> Original change's description:
> > SequenceManager to perform periodic housekeeping (sweep canceled tasks)
> >
> > Long delay canceled tasks can really pile up if we don't activly remove
> > them. We already do that in the renderer but we need to bring this
> > technology to other SequenceMangers.
> >
> > Bug: 863341
> > Change-Id: Ie16674043028090f94c184c02acbef6efcf3471b
> > Reviewed-on: https://chromium-review.googlesource.com/c/1483076
> > Commit-Queue: Alex Clarke <alexclarke@chromium.org>
> > Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
> > Reviewed-by: Alexander Timin <altimin@chromium.org>
> > Reviewed-by: Alex Clarke <alexclarke@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#635497}
> 
> TBR=skyostil@chromium.org,alexclarke@chromium.org,altimin@chromium.org,carlscab@google.com
> 
> # Not skipping CQ checks because original CL landed > 1 day ago.
> 
> Bug: 863341, 936734
> Change-Id: Ie948d9519dee14326137ad04aa88e53207db6eed
> Reviewed-on: https://chromium-review.googlesource.com/c/1495976
> Reviewed-by: Alex Clarke <alexclarke@chromium.org>
> Commit-Queue: Alex Clarke <alexclarke@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#636765}

TBR=skyostil@chromium.org,alexclarke@chromium.org,altimin@chromium.org,carlscab@google.com

Change-Id: I63ec7c7620171c4ee499d78f47dad4bc6cb1218a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 863341, 936734
Reviewed-on: https://chromium-review.googlesource.com/c/1496856
Reviewed-by: Alex Clarke <alexclarke@chromium.org>
Commit-Queue: Alex Clarke <alexclarke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#637115}
16 files changed