Revert "Reland "Enable MessagePumpEpoll by default""

This reverts commit b5ccb17.

Reason for revert: b/260877744

Original change's description:
> Reland "Enable MessagePumpEpoll by default"
>
> This reverts commit c404a85.
>
> Reason for revert: This wasn't the cause of the failure, the failure was fixed by other revert, see bug crbug.com/1382988 
>
> Original change's description:
> > Revert "Enable MessagePumpEpoll by default"
> >
> > This reverts commit 81ade53.
> >
> > Reason for revert: Causing consistent failures on ASAN bots:
> > https://bugs.chromium.org/p/chromium/issues/detail?id=1382988
> >
> > Bug: 1382988
> >
> > Original change's description:
> > > Enable MessagePumpEpoll by default
> > >
> > > This has been on at 50% canary/dev/beta and 1% stable since M106.
> > >
> > > Bug: 1243354
> > > Change-Id: I56551c1ddb65a062a743b47318f92d5030732e9a
> > > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3853515
> > > Reviewed-by: Francois Pierre Doray <fdoray@chromium.org>
> > > Commit-Queue: Ken Rockot <rockot@google.com>
> > > Cr-Commit-Position: refs/heads/main@{#1069422}
> >
> > Bug: 1243354
> > Change-Id: I0fb07eabbed35bc3e9048ed2a562bd8e6a8f3579
> > No-Presubmit: true
> > No-Tree-Checks: true
> > No-Try: true
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4019732
> > Auto-Submit: Luciano Pacheco <lucmult@chromium.org>
> > Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> > Owners-Override: Luciano Pacheco <lucmult@chromium.org>
> > Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> > Cr-Commit-Position: refs/heads/main@{#1069553}
>
> Bug: 1382988
> Bug: 1243354
> Change-Id: I2d1e5d67aa22afe0408696ae99593c8783034759
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4019557
> Owners-Override: Luciano Pacheco <lucmult@chromium.org>
> Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> Commit-Queue: Luciano Pacheco <lucmult@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1069628}

(cherry picked from commit 02d0f24)

Bug: 1382988
Bug: 1243354
Change-Id: I1b5848bdee859ccde2e5cfc340b7f33c66afa9f3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4135841
Reviewed-by: Francois Pierre Doray <fdoray@chromium.org>
Auto-Submit: Ken Rockot <rockot@google.com>
Commit-Queue: Ken Rockot <rockot@google.com>
Commit-Queue: Francois Pierre Doray <fdoray@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1090589}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4156811
Owners-Override: Prudhvikumar Bommana <pbommana@google.com>
Reviewed-by: Ken Rockot <rockot@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Kazuhiro Inaba <kinaba@chromium.org>
Cr-Commit-Position: refs/branch-heads/5414@{#1344}
Cr-Branched-From: 4417ee5-refs/heads/main@{#1070088}

base/message_loop/message_pump_libevent.cc

@@ -44,7 +44,9 @@ namespace {
 #if BUILDFLAG(ENABLE_MESSAGE_PUMP_EPOLL)
 bool g_use_epoll = false;
 
-BASE_FEATURE(kMessagePumpEpoll, "MessagePumpEpoll", FEATURE_ENABLED_BY_DEFAULT);
+BASE_FEATURE(kMessagePumpEpoll,
+             "MessagePumpEpoll",
+             FEATURE_DISABLED_BY_DEFAULT);
 #endif
 
 }  // namespace