GitLab

Partial reland... keep StartWatching() calls to try to isolate
the issue

This is a reland of 91c22dbf
Original change's description:
> Remove hang watching of deprecated BrowserThreads.
>
> This is a partial reland of https://chromium-review.googlesource.com/c/chromium/src/+/705775
>
> That CL caused issue 768886 (spike in hang reports). I suspect this
> was caused by a change in enum IDs rather than this change to the
> hang watching code and this CL will help narrow down the cause.
>
> R=asvitkine@chromium.org
>
> Bug: 689520,768886
> Change-Id: Id7bf1c7b5f5d34c4b1e7b1e71e9b015725695997
> Reviewed-on: https://chromium-review.googlesource.com/743846
> Commit-Queue: Gabriel Charette <gab@chromium.org>
> Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#512509}

Bug: 689520, 768886
Change-Id: I138fc4b33e6316496ff35e927b2cfb5246b53a6d

NOPRESUBMIT=TRUE (shuffling of code using deprecated BrowserThread IDs)

Change-Id: I138fc4b33e6316496ff35e927b2cfb5246b53a6d
Reviewed-on: https://chromium-review.googlesource.com/848355Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Commit-Queue: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#526736}