Revert "Reland "Remove event races in two breakpoint decoration tests""

This reverts commit d4f52942983bb76986851827d8d6a83925c82206.

Reason for revert: Tests become flaky after this CL. Reverting for a more in-depth investigation.

Original change's description:
> Reland "Remove event races in two breakpoint decoration tests"
> 
> This is a reland of 61f9138112dc68bc526ba6255e2927e85d3ade01
> 
> Tentative reland of the CL as-is because:
>   - in the same time there was a general issue with crashing layout tests
>     (especially on Mac)
>   - the issue is not re-producible locally
> 
> Original change's description:
> > Remove event races in two breakpoint decoration tests
> >
> > This CL changes two layout tests to follow the pattern of:
> >   1. Install an instrumentation promise
> >   2. Run and await an async action
> >   3. Await that the instrumentation is called
> >   4. Dump breakpoint information
> >
> > This CL is also in preparation for asyncification of source mapping,
> > hence making the "action" async.
> >
> > Drive-by: Re-baseline one of the layout tests that seems to be fixed
> > now.
> >
> > Bug: chromium:1032016
> > Change-Id: Ibad4160fe9ab32aa3f818cdd4937112c3f4e6f08
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2000023
> > Commit-Queue: Simon Zünd <szuend@chromium.org>
> > Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#731171}
> 
> Bug: chromium:1032016
> Change-Id: I34ec151749a56a1820330546cd0214b0c22c9eaf
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2007458
> Commit-Queue: Simon Zünd <szuend@chromium.org>
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#733313}

TBR=sigurds@chromium.org,szuend@chromium.org

Change-Id: Ic5fcf5a58fe1ff4a49bc2f34195989e2babd1589
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:1032016
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2010844
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#733355}
3 files changed