Reason for revert:
CallPerfTest.ReceivesCpuOveruseAndUnderuse perf test fails due to this CL. It requires very accurate frame rate, which may not be so accurate now.
Original issue's description:
> Reland of rewrite frame generator capturer to use TaskQueue instead of EventTimeWrapper (patchset #1 id:1 of https://codereview.webrtc.org/2743993002/ )
>
> And enable large full-stack test depending on that change (Reland of https://codereview.webrtc.org/2741823003/)
> TBR=stefan@webrtc.org,tommi@webrtc.org
> BUG=webrtc:7301,webrtc:7325
>
> Review-Url: https://codereview.webrtc.org/2744003002
> Cr-Commit-Position: refs/heads/master@{#17196}
> Committed: 8c0a5896d1TBR=stefan@webrtc.org,tommi@webrtc.org,sprang@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7301,webrtc:7325
Review-Url: https://codereview.webrtc.org/2748643002
Cr-Commit-Position: refs/heads/master@{#17198}
382a72a0d3