Example failure:
https://uberchromegw.corp.google.com/i/chromium.linux/builders/Linux%20Tests/builds/67454

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9bc2aee4a51bcf74b5b01d2bc3a5f685d53b7e9f

commit 9bc2aee4a51bcf74b5b01d2bc3a5f685d53b7e9f
Author: chcunningham <chcunningham@chromium.org>
Date: Thu Feb 15 19:34:10 2018

Update expectation for flaky scrollable area test

New test
fast/layers/scrollable-area-removed-on-scroll-crash.html

Test was added yesterday here
https://chromium.googlesource.com/chromium/src/+/3ab971569afab25c6e330b3898fba29288b68732

No-Tree-Checks: true
No-Try: true
TBR: flackr@chromium.org
Bug:  812702 
Change-Id: I456220e68f10a39fd607bbce55b5300ff25041e6
Reviewed-on: https://chromium-review.googlesource.com/922266
Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Commit-Queue: Chrome Cunningham <chcunningham@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537099}
[modify] https://crrev.com/9bc2aee4a51bcf74b5b01d2bc3a5f685d53b7e9f/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/14fb4bf71bc1d4e0693b588724c8d6f8ed2d6207

commit 14fb4bf71bc1d4e0693b588724c8d6f8ed2d6207
Author: Robert Flack <flackr@chromium.org>
Date: Fri Feb 16 16:35:34 2018

Fix flakiness in fast/layers/scrollable-area-removed-on-scroll-crash.html

There are multiple accessibility notifications but the test should only
continue when it receives the one for the programmatic scroll.

This patch also fixes another use after free from trying to use the smooth
scroll coordinator.

Bug:  797298 , 812702 
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: I1340d8cd1d5d3e53e75d9ab0c5f50b523041b187
Reviewed-on: https://chromium-review.googlesource.com/922685
Commit-Queue: Robert Flack <flackr@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537317}
[modify] https://crrev.com/14fb4bf71bc1d4e0693b588724c8d6f8ed2d6207/third_party/WebKit/LayoutTests/TestExpectations
[modify] https://crrev.com/14fb4bf71bc1d4e0693b588724c8d6f8ed2d6207/third_party/WebKit/LayoutTests/fast/layers/scrollable-area-removed-on-scroll-crash.html
[modify] https://crrev.com/14fb4bf71bc1d4e0693b588724c8d6f8ed2d6207/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp