Looks like it flakes pretty often.
https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=webkit_layout_tests%20(with%20patch)&tests=fast%2Fcanvas%2Fcolor-space%2Fcanvas-colorManaged-convertToBlob-roundtrip.html

full test name:
fast/canvas/color-space/canvas-colorManaged-convertToBlob-roundtrip.html
virtual/gpu/fast/canvas/color-space/canvas-colorManaged-convertToBlob-roundtrip.html

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1d647a8b8e8bd1e1fa477c4492653b5f0bf49f89

commit 1d647a8b8e8bd1e1fa477c4492653b5f0bf49f89
Author: Mark Pearson <mpearson@chromium.org>
Date: Tue Jun 12 00:10:01 2018

Disable canvas-colorManaged-convertToBlob-roundtrip.html Due to Timeouts

fast/canvas/color-space/canvas-colorManaged-convertToBlob-roundtrip.html
virtual/gpu/fast/canvas/color-space/canvas-colorManaged-convertToBlob-roundtrip.html

They flakily time out.

TBR=zakerinasab
NOTRY=true

Bug:  851746 
Change-Id: I835eba334d112ee3c7200f1f83b4718f85a03391
Reviewed-on: https://chromium-review.googlesource.com/1096442
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Commit-Queue: Mark Pearson <mpearson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566215}
[modify] https://crrev.com/1d647a8b8e8bd1e1fa477c4492653b5f0bf49f89/third_party/WebKit/LayoutTests/TestExpectations

Removing from sheriff queue.

This is strange since the tests have failed first with unanticipated pixel results when drawing sRGB image on a wide gamut canvas and creating the blob in sRGB. Then the tests time out on the next tries. I tried to see if this is happening due to the order of the tests running on a worker, but seems to be unrelated. Also I cannot reproduce the flakiness on my local machine. I think this might have happened temporarily while Skia was fixing their color conversion code path for non-linear gamma function color spaces (including sRGB).

Reactivating the tests and monitoring the bots to see if the flakiness returns.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/50abe8b73cd44cb02e11a56dca549541e96d755d

commit 50abe8b73cd44cb02e11a56dca549541e96d755d
Author: Reza.Zakerinasab <zakerinasab@chromium.org>
Date: Tue Jul 03 18:30:44 2018

Remove timeout tag for canvas-colorManaged-convertToBlob-roundtrip layout test

The flakiness cannot be reproduced and suspected to be a result of recent changes
in Skia color management code. Removing timeout tag for the tests and monitoring
the bots to see if the flakiness returns.

TBR=fserb@chromium.org

Bug:  851746 
Change-Id: Ie9f3e650140be4b9f27e9e7963ead014cee2bf49
Reviewed-on: https://chromium-review.googlesource.com/1124986
Reviewed-by: Mohammad Reza Zakerinasab <zakerinasab@chromium.org>
Commit-Queue: Mohammad Reza Zakerinasab <zakerinasab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572299}
[modify] https://crrev.com/50abe8b73cd44cb02e11a56dca549541e96d755d/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/40491101a69732246e97bb33f41770571bb66d35

commit 40491101a69732246e97bb33f41770571bb66d35
Author: Reza.Zakerinasab <zakerinasab@chromium.org>
Date: Wed Jul 04 14:29:59 2018

Flag canvas-colorManaged-convertToBlob-roundtrip.html to timeout

fast/canvas/color-space/canvas-colorManaged-convertToBlob-roundtrip.html
virtual/gpu/fast/canvas/color-space/canvas-colorManaged-convertToBlob-roundtrip.html

They flakily time out.

TBR=fserb
NOTRY=true

Bug:  851746 
Change-Id: Ib32001de56c74350a016e124fb5fa7e8906b5b04
Reviewed-on: https://chromium-review.googlesource.com/1126202
Reviewed-by: Mohammad Reza Zakerinasab <zakerinasab@chromium.org>
Commit-Queue: Mohammad Reza Zakerinasab <zakerinasab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572561}
[modify] https://crrev.com/40491101a69732246e97bb33f41770571bb66d35/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/dacbdbe8413f065d4dbe280a48e63094b35afb43

commit dacbdbe8413f065d4dbe280a48e63094b35afb43
Author: Ella Ge <eirage@chromium.org>
Date: Wed Jul 04 21:22:04 2018

Disable canvas-colorManaged-convertToBlob-roundtrip.html

These two tests also timeout on other platform.
fast/canvas/color-space/canvas-colorManaged-convertToBlob-roundtrip.html
virtual/gpu/fast/canvas/color-space/canvas-colorManaged-convertToBlob-roundtrip.html

Flakiness dashboard:
https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=webkit_layout_tests&tests=fast%2Fcanvas%2Fcolor-space%2Fcanvas-colorManaged-convertToBlob-roundtrip.html

TBR=zakerinasab@chromium.org
NOTRY=true

Bug:  851746 
Change-Id: If09ac46ad59da449fa2186d0664707141e544a3a
Reviewed-on: https://chromium-review.googlesource.com/1126485
Reviewed-by: Ella Ge <eirage@chromium.org>
Commit-Queue: Ella Ge <eirage@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572657}
[modify] https://crrev.com/dacbdbe8413f065d4dbe280a48e63094b35afb43/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2f87aeb83b5e20a141f091d8dd0b63c19cc0432a

commit 2f87aeb83b5e20a141f091d8dd0b63c19cc0432a
Author: Dirk Pranke <dpranke@chromium.org>
Date: Tue Jul 10 21:19:03 2018

Adjust bug number for a flaky test in TestExpectations.

 Bug 851746  was duped into  bug 860706 , so this updates the entry.

TBR=fserb@chromium.org
NOTRY=true
BUG= 851746 ,  860706 

Change-Id: I8f1e9e4b2c5e606f20459cc0121ca8c2c65211ee
Reviewed-on: https://chromium-review.googlesource.com/1132322
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#573910}
[modify] https://crrev.com/2f87aeb83b5e20a141f091d8dd0b63c19cc0432a/third_party/WebKit/LayoutTests/TestExpectations