The former was fixed by previous sheriff in r500332.

The following tests are timing out:

virtual/gpu-rasterization/images/color-profile-border-radius.html (always)
virtual/gpu-rasterization/images/color-profile-image-canvas-svg.html (sometimes)

First failing build on each bot:
https://luci-milo.appspot.com/buildbot/chromium.webkit/WebKit%20Mac10.9/49682 [500360..500366]
https://luci-milo.appspot.com/buildbot/chromium.webkit/WebKit%20Mac10.10/37393 [500363..500366]
https://luci-milo.appspot.com/buildbot/chromium.webkit/WebKit%20Mac10.11/23301 [500365..500374]

r500366 highly suspect (Skia DEPS roll)

Within that roll, the suspect is https://skia-review.googlesource.com/c/skia/+/43183 (2017-09-07 junov Optimize SkColorSpaceXformCanvas for GPU-acceleration)

According to http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium#TOC-Failures-due-to-DEPS-rolls, reverting the DEPS roll.

Robert (Skia sheriff) can you investigate and resume rolling when this looks good?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b81dee7bb2af6c7940eec41db2db93e281bc2e59

commit b81dee7bb2af6c7940eec41db2db93e281bc2e59
Author: Matt Giuca <mgiuca@chromium.org>
Date: Fri Sep 08 03:51:15 2017

Revert "Roll src/third_party/skia/ 6d9e4ee14..e5ede4b13 (23 commits)"

This reverts commit a2ac4a2a3faa0d2307e1cc4d7d7e82675a796f0a and
c14495093d88203534ab85a4ce22febf215b5084 (two rolls have been reverted).

Reason for revert: Suspect broke Mac layout tests; see bug.

Bug: 763197

Original change's description:
> Roll src/third_party/skia/ 6d9e4ee14..e5ede4b13 (23 commits)
>
> https://skia.googlesource.com/skia.git/+log/6d9e4ee14e7e..e5ede4b138e8
>
> $ git log 6d9e4ee14..e5ede4b13 --date=short --no-merges --format='%ad %ae %s'
> 2017-09-07 csmartdalton Revert "Improve GrPathRendererChain heuristics"
> 2017-09-07 bsalomon Update mtl backend to use GrSamplerState
> 2017-09-07 junov Optimize SkColorSpaceXformCanvas for GPU-acceleration
> 2017-09-04 csmartdalton Improve GrPathRendererChain heuristics
> 2017-09-07 bsalomon Rework GrSamplerParams to be more compact and use its own wrap mode enum.
> 2017-09-07 bsalomon Revert "Remove "content" rect from GrTextureAdjuster."
> 2017-09-07 brianosman Blacklist more flaky GMs in gltestthreading config
> 2017-09-07 bsalomon Remove "content" rect from GrTextureAdjuster.
> 2017-09-07 angle-deps-roller Roll skia/third_party/externals/angle2/ 61e710b65..7cadfcc70 (1 commit)
> 2017-09-07 brianosman Make SkImage_Lazy always report the color space of its data
> 2017-09-06 rmistry Add links to autoroller cloud logs for roboCops
> 2017-09-07 ethannicholas Fix for Google3 roll failure
> 2017-09-07 rmistry Revert "Whitespace change to test Android autoroller"
> 2017-09-07 rmistry Whitespace change to test Android autoroller
> 2017-07-10 nagarajan.n Remove loop unrolling code in load_gamut
> 2017-07-19 nagarajan.n Remove loop unrolling code in onQueryYUV8
> 2017-07-19 nagarajan.n Update libjpeg buffer status when it has has to be refilled.
> 2017-09-06 liyuqian Fix SkASSERT for convex paths with DAA
> 2017-09-07 ethannicholas Revert "Revert "Initial checkin of SkSL lexical analyzer generator (not actually in use yet).""
> 2017-09-06 brianosman Output encoded PNGs when gltestthreading or serialize fails
> 2017-08-30 bsalomon Add rect clip optimization to GrRenderTargetContext::drawTextureAffine
> 2017-09-07 caryclark remove useless reset
> 2017-09-07 angle-deps-roller Roll skia/third_party/externals/angle2/ c1d4e5509..61e710b65 (1 commit)
>
> Created with:
>   roll-dep src/third_party/skia
> BUG= 760738 
>
>
> Documentation for the AutoRoller is here:
> https://skia.googlesource.com/buildbot/+/master/autoroll/README.md
>
> If the roll is causing failures, see:
> http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium#TOC-Failures-due-to-DEPS-rolls
>
>
> CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
> TBR=robertphillips@chromium.org
>
> Change-Id: I2dbf077343bff9386a6f2a948261c7e190f03733
> Reviewed-on: https://chromium-review.googlesource.com/655762
> Reviewed-by: Skia Deps Roller <skia-deps-roller@chromium.org>
> Commit-Queue: Skia Deps Roller <skia-deps-roller@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#500366}

TBR=skia-deps-roller@chromium.org,robertphillips@google.com

Change-Id: I996f952cec94afb43d558e279eef2f8b2c8d02a1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  760738 
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
Reviewed-on: https://chromium-review.googlesource.com/656738
Commit-Queue: Matt Giuca <mgiuca@chromium.org>
Reviewed-by: Matt Giuca <mgiuca@chromium.org>
Cr-Commit-Position: refs/heads/master@{#500501}
[modify] https://crrev.com/b81dee7bb2af6c7940eec41db2db93e281bc2e59/DEPS

The test is fixed now on all three builders.

Note the Mac 10.9 builder is still failing due to an unrelated bug ( Issue 763252 ).

I have reverted the suspect CL and am re-rolling in https://chromium-review.googlesource.com/c/chromium/src/+/657478

FWIW, I added the mac10.9_blink_rel, mac10.10_blink_rel and mac10.11_blink_rel trybots. Two of them are green at this point so I'm going to let the roll land.

I investigated why these tests are timing out.
It is due to a performance regression that only affects layout tests.  So I am just going to mark these tests as slow on mac then re-land the skia patch.

What is happening with the culprit CL is that it moves to the GPU some image processing work that used to be performed on the CPU, in order to get a performance boost.  However, when running in layout test mode, the gpu-rasterization tests don't use a real gpu.  The gpu is emulated in software using the mesa library, which is actually slower.

I was able to repro the slow down locally on my Mac, it does not time out locally, but the test takes 4s to run (which is pretty slow). When I run the test in a Chromium build instead of content_shell, the test runs in less than 0.3s.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0789a62ba6376f0ccb522ded0c8e006d2180232b

commit 0789a62ba6376f0ccb522ded0c8e006d2180232b
Author: Justin Novosad <junov@chromium.org>
Date: Fri Sep 08 19:25:53 2017

Marking some tests as slow before re-landing skia CL that slows them

This change marks the following tests as slow on mac:
virtual/gpu-rasterization/images/color-profile-border-radius.html
virtual/gpu-rasterization/images/color-profile-image-canvas-svg.html

This will allow https://skia-review.googlesource.com/c/skia/+/43183
to reland in skia without causing failures.

The reason the test are becoming slow is that the skia change
causes color space conversion work to be performed on the GPU
instead of the CPU.  The GPU path is slower when running layout
tests because for layout tests we use mesa instead of real GPUs.

TBR=xidachen@chromium.org
NOTRY=true
BUG=763197,  760738 

Change-Id: I4e0dcf30add90022d71bb6e3ac2d90b48380d625
Reviewed-on: https://chromium-review.googlesource.com/657883
Reviewed-by: Justin Novosad <junov@chromium.org>
Commit-Queue: Justin Novosad <junov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#500639}
[modify] https://crrev.com/0789a62ba6376f0ccb522ded0c8e006d2180232b/third_party/WebKit/LayoutTests/SlowTests

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9f58207a4d6dd16f66b1ab6f0c4fa36f7617052e

commit 9f58207a4d6dd16f66b1ab6f0c4fa36f7617052e
Author: Ben Wells <benwells@chromium.org>
Date: Tue Sep 12 00:56:34 2017

Mark a Layout test as slow

TBR=brucedawson@chromium.org
NOTRY=true

Bug: 763197
Change-Id: Ie99b0e5e2839212cdbe6d01986aa99f31911d64e
Reviewed-on: https://chromium-review.googlesource.com/662257
Reviewed-by: Ben Wells <benwells@chromium.org>
Commit-Queue: Ben Wells <benwells@chromium.org>
Cr-Commit-Position: refs/heads/master@{#501130}
[modify] https://crrev.com/9f58207a4d6dd16f66b1ab6f0c4fa36f7617052e/third_party/WebKit/LayoutTests/SlowTests

This test appears to also be slow on Linux:

https://uberchromegw.corp.google.com/i/chromium.linux/builders/Linux%20Tests/builds/62528

Marking it as such.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1d5a43ce818c670dc385bff988423fdd90b1f69e

commit 1d5a43ce818c670dc385bff988423fdd90b1f69e
Author: Elly Fong-Jones <ellyjones@chromium.org>
Date: Thu Sep 21 14:38:48 2017

sheriff: mark some rasterization tests as slow on linux

Bug: 763197
Change-Id: Ieffbc7c47c45cc2e8edf8969488e00633c892de2
TBR: brucedawson@chromium.org
No-Tree-Checks: True
Reviewed-on: https://chromium-review.googlesource.com/677266
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#503446}
[modify] https://crrev.com/1d5a43ce818c670dc385bff988423fdd90b1f69e/third_party/WebKit/LayoutTests/SlowTests

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