Sample log

=====
07:21:43.568 4516 worker/1 virtual/mouseevent_fractional/fast/events/touch/gesture/gesture-tap-hover-state-iframe.html output stderr lines:
07:21:43.568 4516   
07:21:43.568 4516   DevTools listening on ws://127.0.0.1:60507/devtools/browser/a2d5a024-14d4-4f44-a806-bc106ab891cd
07:21:43.568 4516   [5448:7304:0128/072140.535:INFO:media_foundation_video_encode_accelerator_win.cc(370)] Windows versions earlier than 8 are not supported.
07:21:43.572 2260 [5/7] virtual/mouseevent_fractional/fast/events/touch/gesture/gesture-tap-hover-state-iframe.html failed unexpectedly (text diff)
07:21:43.571 4516 worker/1 virtual/mouseevent_fractional/fast/events/touch/gesture/gesture-tap-hover-state-iframe.html failed:
07:21:43.571 4516 worker/1  text diff
07:21:43.571 4516 worker/1 killing secondary driver
07:21:43.572 4516 worker/1 exiting
07:21:43.572 4516 worker/1 cleaning up
07:21:43.572 4516 worker/1 killing primary driver
07:21:43.610 4516 "taskkill.exe /f /t /pid 6316" took 0.04s
07:21:43.610 4516 killed pid 6316
07:21:43.610 4516 worker/1 killing secondary driver
====

the test name is virtual/mouseevent_fractional/fast/events/touch/gesture/gesture-tap-hover-state-iframe.html

the CL to disable the test is https://chromium-review.googlesource.com/c/chromium/src/+/891229.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/589a7d6685beff4ecf3b44237207d034e9a08d84

commit 589a7d6685beff4ecf3b44237207d034e9a08d84
Author: vitaliii <vitaliii@chromium.org>
Date: Mon Jan 29 15:29:31 2018

Disable v/m/f/e/t/g/gesture-tap-hover-state-iframe.html on Win7 (flaky).

Disable virtual/mouseevent_fractional/fast/events/touch/gesture/gesture-
tap-hover-state-iframe.html on Win7, because if fails flakily.

TBR=dtapuska@chromium.org

Bug:  806748 , 806735 
Change-Id: I6b80a90cd973a62258a9961f1018124cd0f26572
Reviewed-on: https://chromium-review.googlesource.com/891229
Commit-Queue: vitaliii <vitaliii@chromium.org>
Reviewed-by: vitaliii <vitaliii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532438}
[modify] https://crrev.com/589a7d6685beff4ecf3b44237207d034e9a08d84/third_party/WebKit/LayoutTests/TestExpectations

Please have a look.

Ella, please investigate.

@eirage@ can you PTAL since it is a loss of test coverage?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/548c71e058f220820630dfcaa307f8462bbc4645

commit 548c71e058f220820630dfcaa307f8462bbc4645
Author: Ella Ge <eirage@chromium.org>
Date: Thu Feb 08 00:14:26 2018

Set cursor visibility in gesture-tap-hover test.

GestureEvents hover states layout tests flaky because fake mouse
move was fired between two tap. Set cursor invisible to prevent
fake events firing.

Bug:  806748 , 795250 
Change-Id: I81859362a1eb80810e875fd9d513689eaa3f0843
Reviewed-on: https://chromium-review.googlesource.com/898005
Commit-Queue: Ella Ge <eirage@chromium.org>
Reviewed-by: Navid Zolghadr <nzolghadr@chromium.org>
Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#535205}
[modify] https://crrev.com/548c71e058f220820630dfcaa307f8462bbc4645/third_party/WebKit/LayoutTests/FlagExpectations/disable-blink-features=RootLayerScrolling
[modify] https://crrev.com/548c71e058f220820630dfcaa307f8462bbc4645/third_party/WebKit/LayoutTests/TestExpectations
[modify] https://crrev.com/548c71e058f220820630dfcaa307f8462bbc4645/third_party/WebKit/LayoutTests/fast/events/touch/gesture/gesture-tap-hover-state-iframe.html

Thank you!