The list of flakes shows this happening on win_chromium_rel_ng. Looking at the logs from a failure shows
16:24:06.850 5024 [684/41249] virtual/gpu-rasterization/fast/images/color-profile-filter.html failed unexpectedly (test timed out)

The flakiness dashboard
http://test-results.appspot.com/dashboards/flakiness_dashboard.html#showAllRuns=true&showLargeExpectations=true&tests=virtual%2Fgpu-rasterization%2Ffast%2Fimages%2Fcolor-profile-filter.html
already has TIMEOUT expectations listed for Linux and Mac for this test, but nothing for Win.

noel@ recommended marking the test as slow in LayoutTests/SlowTests. Patch forthcoming.

https://codereview.chromium.org/2010373002 is being committed. If the test still times out even when marked as slow, consider marking it with TIMEOUT in TestExpectations.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8ef20b1ec860af9d0416a1314b91f89802d4318f

commit 8ef20b1ec860af9d0416a1314b91f89802d4318f
Author: suzyh <suzyh@chromium.org>
Date: Fri May 27 06:52:03 2016

Mark color-profile-filter.html test as slow.

Flaky test timing out in virtual/ on Windows. Already marked as
timing out on other platforms.

BUG=614910

Review-Url: https://codereview.chromium.org/2010373002
Cr-Commit-Position: refs/heads/master@{#396412}

[modify] https://crrev.com/8ef20b1ec860af9d0416a1314b91f89802d4318f/third_party/WebKit/LayoutTests/SlowTests

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9075f10d3c1d1e90308e31c9c7783d6626476f87

commit 9075f10d3c1d1e90308e31c9c7783d6626476f87
Author: schenney <schenney@chromium.org>
Date: Wed Aug 24 20:47:24 2016

Move slow virtual/gpu-rasterization/fast/images/pixel-crack-image-background-webkit-transform-scale.html to SlowTests

TBR=noel@chromium.org
BUG=614910

Review-Url: https://codereview.chromium.org/2265333002
Cr-Commit-Position: refs/heads/master@{#414136}

[modify] https://crrev.com/9075f10d3c1d1e90308e31c9c7783d6626476f87/third_party/WebKit/LayoutTests/SlowTests
[modify] https://crrev.com/9075f10d3c1d1e90308e31c9c7783d6626476f87/third_party/WebKit/LayoutTests/TestExpectations
[add] https://crrev.com/9075f10d3c1d1e90308e31c9c7783d6626476f87/third_party/WebKit/LayoutTests/platform/android/virtual/gpu-rasterization/fast/images/pixel-crack-image-background-webkit-transform-scale-expected.png
[add] https://crrev.com/9075f10d3c1d1e90308e31c9c7783d6626476f87/third_party/WebKit/LayoutTests/platform/linux/virtual/gpu-rasterization/fast/images/pixel-crack-image-background-webkit-transform-scale-expected.png
[add] https://crrev.com/9075f10d3c1d1e90308e31c9c7783d6626476f87/third_party/WebKit/LayoutTests/platform/mac-mac10.10/virtual/gpu-rasterization/fast/images/pixel-crack-image-background-webkit-transform-scale-expected.png
[add] https://crrev.com/9075f10d3c1d1e90308e31c9c7783d6626476f87/third_party/WebKit/LayoutTests/platform/mac-mac10.9/virtual/gpu-rasterization/fast/images/pixel-crack-image-background-webkit-transform-scale-expected.png
[add] https://crrev.com/9075f10d3c1d1e90308e31c9c7783d6626476f87/third_party/WebKit/LayoutTests/platform/mac-retina/virtual/gpu-rasterization/fast/images/pixel-crack-image-background-webkit-transform-scale-expected.png
[add] https://crrev.com/9075f10d3c1d1e90308e31c9c7783d6626476f87/third_party/WebKit/LayoutTests/platform/mac/virtual/gpu-rasterization/fast/images/pixel-crack-image-background-webkit-transform-scale-expected.png
[add] https://crrev.com/9075f10d3c1d1e90308e31c9c7783d6626476f87/third_party/WebKit/LayoutTests/platform/win/virtual/gpu-rasterization/fast/images/pixel-crack-image-background-webkit-transform-scale-expected.png

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0b70c48aa9a1d5e511973eddb3a2fe3d03ebb7d8

commit 0b70c48aa9a1d5e511973eddb3a2fe3d03ebb7d8
Author: johnme <johnme@chromium.org>
Date: Thu Aug 25 12:09:13 2016

Mark pixel-crack-image-background-webkit-transform-scale failing on Mac

Test
virtual/gpu-rasterization/fast/images/pixel-crack-image-background-webkit-transform-scale.html
has been failing consistently on WebKit Mac10.10, WebKit Mac10.11
(retina) and mac10.10_blink_rel tryserver, for as far back as the
flakiness dashboard can show (which in practice is when
https://codereview.chromium.org/2265333002 added it to SlowTests; before
that it always timed out). However it always passes on other Mac bots.

BUG=614910
NOTRY=true
NOTREECHECKS=true
TBR=noel@chromium.org,schenney@chromium.org

Review-Url: https://codereview.chromium.org/2270693010
Cr-Commit-Position: refs/heads/master@{#414401}

[modify] https://crrev.com/0b70c48aa9a1d5e511973eddb3a2fe3d03ebb7d8/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/858bfb659e50d2d2debebd92847c59b884848ae4

commit 858bfb659e50d2d2debebd92847c59b884848ae4
Author: schenney <schenney@chromium.org>
Date: Wed Apr 05 21:52:46 2017

Move Paint Team TestExpectations lines into appropriate sections

This completes a review of all the Paint Team owned layout test
failures. With this patch tests are grouped so we know which ones
might be worth investigating in the future and so we can more
easily incorporate new failures.

There is one outstanding patch to be comnitted rebasing one set
of tests.

TBR=chrishtr@chromium.org
BUG=309675,504613, 517449 , 549742 , 602110 , 606302 ,614910, 676561 

Review-Url: https://codereview.chromium.org/2803633005
Cr-Commit-Position: refs/heads/master@{#462231}

[modify] https://crrev.com/858bfb659e50d2d2debebd92847c59b884848ae4/third_party/WebKit/LayoutTests/NeverFixTests
[modify] https://crrev.com/858bfb659e50d2d2debebd92847c59b884848ae4/third_party/WebKit/LayoutTests/TestExpectations

This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f73246ba7034539dbda70502ec21b53b06cd68b3

commit f73246ba7034539dbda70502ec21b53b06cd68b3
Author: Alexis Hetu <sugoi@google.com>
Date: Wed Jun 06 16:56:27 2018

Re-enable some disabled MacOS Layout Tests

Now that synchronization issues have been fixed on MacOS,
most previously disabled layout tests can be re-enabled.

TBR=kbr@chromium.org
Bug: chromium:726075   chromium:646528   chromium:845267  chromium:614910  chromium:845266  chromium:791941  chromium:847094   chromium:849256 

Change-Id: Ifa59c2594c429a94643ea9f19b2e08e974cc6c53
Reviewed-on: https://chromium-review.googlesource.com/1088197
Reviewed-by: Alexis Hétu <sugoi@chromium.org>
Commit-Queue: Alexis Hétu <sugoi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#564927}
[modify] https://crrev.com/f73246ba7034539dbda70502ec21b53b06cd68b3/third_party/WebKit/LayoutTests/SlowTests
[modify] https://crrev.com/f73246ba7034539dbda70502ec21b53b06cd68b3/third_party/WebKit/LayoutTests/TestExpectations
[delete] https://crrev.com/2db1569218f1a28d439fcf3b031b9cce41a2f771/third_party/WebKit/LayoutTests/platform/mac-mac10.10/virtual/gpu-rasterization/images/color-profile-border-image-expected.png
[modify] https://crrev.com/f73246ba7034539dbda70502ec21b53b06cd68b3/third_party/WebKit/LayoutTests/platform/mac-mac10.10/virtual/gpu-rasterization/images/color-profile-munsell-adobe-to-srgb-expected.png
[modify] https://crrev.com/f73246ba7034539dbda70502ec21b53b06cd68b3/third_party/WebKit/LayoutTests/platform/mac-mac10.10/virtual/gpu-rasterization/images/color-profile-munsell-srgb-to-srgb-expected.png
[delete] https://crrev.com/2db1569218f1a28d439fcf3b031b9cce41a2f771/third_party/WebKit/LayoutTests/platform/mac-mac10.10/virtual/gpu-rasterization/images/pixel-crack-image-background-webkit-transform-scale-expected.png
[delete] https://crrev.com/2db1569218f1a28d439fcf3b031b9cce41a2f771/third_party/WebKit/LayoutTests/platform/mac-mac10.11/virtual/gpu-rasterization/images/color-profile-background-image-cover-expected.png
[delete] https://crrev.com/2db1569218f1a28d439fcf3b031b9cce41a2f771/third_party/WebKit/LayoutTests/platform/mac-mac10.12/virtual/gpu-rasterization/images/color-profile-background-image-cover-expected.png
[delete] https://crrev.com/2db1569218f1a28d439fcf3b031b9cce41a2f771/third_party/WebKit/LayoutTests/platform/mac-retina/virtual/gpu-rasterization/images/color-profile-border-image-expected.png
[delete] https://crrev.com/2db1569218f1a28d439fcf3b031b9cce41a2f771/third_party/WebKit/LayoutTests/platform/mac-retina/virtual/gpu-rasterization/images/pixel-crack-image-background-webkit-transform-scale-expected.png
[modify] https://crrev.com/f73246ba7034539dbda70502ec21b53b06cd68b3/third_party/WebKit/LayoutTests/platform/mac/virtual/gpu-rasterization/images/color-profile-munsell-adobe-to-srgb-expected.png
[modify] https://crrev.com/f73246ba7034539dbda70502ec21b53b06cd68b3/third_party/WebKit/LayoutTests/platform/mac/virtual/gpu-rasterization/images/color-profile-munsell-srgb-to-srgb-expected.png
[modify] https://crrev.com/f73246ba7034539dbda70502ec21b53b06cd68b3/third_party/WebKit/LayoutTests/platform/mac/virtual/gpu-rasterization/images/pixel-crack-image-background-webkit-transform-scale-expected.png
[delete] https://crrev.com/2db1569218f1a28d439fcf3b031b9cce41a2f771/third_party/WebKit/LayoutTests/platform/win/virtual/gpu-rasterization/images/color-profile-background-image-cover-expected.png
[delete] https://crrev.com/2db1569218f1a28d439fcf3b031b9cce41a2f771/third_party/WebKit/LayoutTests/platform/win/virtual/gpu-rasterization/images/color-profile-clip-expected.png
[modify] https://crrev.com/f73246ba7034539dbda70502ec21b53b06cd68b3/third_party/WebKit/LayoutTests/virtual/gpu-rasterization/images/color-profile-background-image-cover-expected.png
[modify] https://crrev.com/f73246ba7034539dbda70502ec21b53b06cd68b3/third_party/WebKit/LayoutTests/virtual/gpu-rasterization/images/color-profile-clip-expected.png

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fa8b12920e8c2042e47816d004b113c155e81aee

commit fa8b12920e8c2042e47816d004b113c155e81aee
Author: Alexis Hetu <sugoi@google.com>
Date: Fri Jul 06 14:14:32 2018

Attempt to unmark some tests as slow/timeout

Now that SwiftShader is on Linux/Windows/MacOS and that a recent
performance improvement has been landed in SwiftShader, verify
which tests still require the Slow/Timeout markers and which don't.

TBR=kbr@chromium.org

Bug:chromium:24182  chromium:433711  chromium:763197  chromium:311482   chromium:243871   chromium:664857   chromium:9798   chromium:237270   chromium:241576   chromium:241869   chromium:246749   chromium:535478   chromium:363029   chromium:364225   chromium:552556   chromium:570656   chromium:584807  chromium:614910  chromium:791659   chromium:726075   chromium:808153  chromium:816045  chromium:693568  chromium:626703 chromium:703533 chromium:786641  chromium:799137   chromium:831686   chromium:831230  chromium:818324  chromium:810437   chromium:847205  chromium:848799  chromium:828962   chromium:849284   chromium:855055 

Change-Id: I5d36d20bd87b234fefe4da3ea7e4af039c0188cb
Reviewed-on: https://chromium-review.googlesource.com/1102341
Reviewed-by: Alexis Hétu <sugoi@chromium.org>
Commit-Queue: Alexis Hétu <sugoi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572962}
[modify] https://crrev.com/fa8b12920e8c2042e47816d004b113c155e81aee/third_party/WebKit/LayoutTests/SlowTests
[modify] https://crrev.com/fa8b12920e8c2042e47816d004b113c155e81aee/third_party/WebKit/LayoutTests/TestExpectations