Re-enable custom-scrollbar-changing-style-relayout-body-scrollablearea

The test seems to not be flaky any more with improvements made to the
web test harness for site isolation. If wrong.. we can revert and
investigate.

Local run of 20 runs had 0 failures and TestExpectations claims it was
very flaky.

R=vmpstr@chromium.org

Bug: 891427
Change-Id: Ia1f35a741436042a14f79a0df4e01e4dc76ff829
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2232747Reviewed-by: vmpstr <vmpstr@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#775743}

third_party/blink/web_tests/TestExpectations

@@ -1383,16 +1383,7 @@ crbug.com/891427 tables/mozilla_expected_failures/marvin/table_overflow_dirty_re
 # The following fail only on Mac.
 crbug.com/891427 [ Mac ] fast/events/touch/gesture/touch-gesture-scroll-listbox.html [ Pass Failure Timeout Crash ]
 
-# These 6 are special. They are tied to both of these CLs:
-#   - https://chromium-review.googlesource.com/c/chromium/src/+/1213864
-#   - https://chromium-review.googlesource.com/c/chromium/src/+/1308038
-# and they only seem (really) flaky when the second CL is in place. But I believe
-# they are related to timing and to the same issues as above.
-# Here is an example: https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_chromium_rel_ng/221340
 crbug.com/891427 paint/invalidation/scroll/fixed-img-src-change-after-scroll.html [ Pass Failure Timeout Crash ]
-crbug.com/891427 virtual/prefer_compositing_to_lcd_text/scrollbars/custom-scrollbar-changing-style-relayout-body-scrollablearea.html [ Pass Failure Timeout Crash ]
-crbug.com/891427 virtual/prefer_compositing_to_lcd_text/scrollbars/custom-scrollbar-changing-style-relayout-div-body-scrollablearea.html [ Pass Failure Timeout Crash ]
-
 # ====== OOPIF-mode failures until here ======
 
 # ====== Form Controls Refresh (chrome://flags/#form-controls-refresh) failures from here ======