Actually, webtiming-ssl.php is also flaky, which was already marked so in TestExpectations, but linked to  issue 678492 . That bug is more specific to failures with site isolation and has been closed. I'll change the bug link of the expectation for webtiming-ssl.php to this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ffc0a9ad35a93978c377adfc3c09c630bb8f77cf

commit ffc0a9ad35a93978c377adfc3c09c630bb8f77cf
Author: Robert Ma <robertma@chromium.org>
Date: Fri Jan 12 19:31:41 2018

Mark webtiming-resolution.html as flaky on Windows

Also change the bug link for webtiming-ssl.php. The original bug was specific
to site isolation and has been closed. The two flaky tests are most likely
related.

Bug:  801341 ,  678492 
Change-Id: Id229084f00f32e32dbf0841da044d20cb819dc16
Reviewed-on: https://chromium-review.googlesource.com/862684
Reviewed-by: Nicolás Peña Moreno <npm@chromium.org>
Commit-Queue: Robert Ma <robertma@chromium.org>
Cr-Commit-Position: refs/heads/master@{#529018}
[modify] https://crrev.com/ffc0a9ad35a93978c377adfc3c09c630bb8f77cf/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/874bac6e00e5b0b5fe291cc51518e5fd1e83c69d

commit 874bac6e00e5b0b5fe291cc51518e5fd1e83c69d
Author: Sami Kyostila <skyostil@chromium.org>
Date: Tue Jan 16 12:23:57 2018

Ensure clamped time always moves forward

This patch fixes a problem where performance.now or Date.now can in rare cases
move slightly backwards due to a loss of arithmetic precision.

BUG= 801341 , 799127 ,798964

Change-Id: I3618933e9697319bb0c2ffb1e7917078d418b488
Reviewed-on: https://chromium-review.googlesource.com/867062
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Sami Kyöstilä <skyostil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#529407}
[modify] https://crrev.com/874bac6e00e5b0b5fe291cc51518e5fd1e83c69d/gin/v8_platform.cc
[modify] https://crrev.com/874bac6e00e5b0b5fe291cc51518e5fd1e83c69d/third_party/WebKit/LayoutTests/TestExpectations
[modify] https://crrev.com/874bac6e00e5b0b5fe291cc51518e5fd1e83c69d/third_party/WebKit/Source/platform/TimeClamper.cpp
[modify] https://crrev.com/874bac6e00e5b0b5fe291cc51518e5fd1e83c69d/third_party/WebKit/Source/platform/TimeClamperTest.cpp

skyostil@, http/tests/misc/webtiming-ssl.php is still flaky after your fix.

Sorry, I meant http/tests/misc/webtiming-resolution.html

Example failure on CQ: https://ci.chromium.org/buildbot/tryserver.chromium.win/win7_chromium_rel_ng/82848

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/77fbb3eebd5d2e4a02c191e326cc26454692df3a

commit 77fbb3eebd5d2e4a02c191e326cc26454692df3a
Author: Nicolas Pena <npm@chromium.org>
Date: Mon Jan 22 18:14:21 2018

Mark test webtiming-resolution.html as flaky

It is flaky on Win as shown in:
https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=webkit_layout_tests&tests=http%2Ftests%2Fmisc%2Fwebtiming-resolution.html

The test will be redone when moved to external/wpt.

Bug:  801341 
Change-Id: Ie6f45173dfa2bf2ca4221ed01f6db5f61460a576
Reviewed-on: https://chromium-review.googlesource.com/878921
Reviewed-by: Robert Ma <robertma@chromium.org>
Commit-Queue: Nicolás Peña Moreno <npm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#530913}
[modify] https://crrev.com/77fbb3eebd5d2e4a02c191e326cc26454692df3a/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/50e671d0abbcaa3b4013a229c9759b33c77daf25

commit 50e671d0abbcaa3b4013a229c9759b33c77daf25
Author: Matt Falkenhagen <falken@chromium.org>
Date: Wed Jan 24 02:15:37 2018

M64: Ensure clamped time always moves forward

This patch fixes a problem where performance.now or Date.now can in rare cases
move slightly backwards due to a loss of arithmetic precision.

BUG= 801341 , 799127 ,798964
TBR=skyostil@chromium.org

(cherry picked from commit 874bac6e00e5b0b5fe291cc51518e5fd1e83c69d)

Change-Id: I3618933e9697319bb0c2ffb1e7917078d418b488
Reviewed-on: https://chromium-review.googlesource.com/867062
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Sami Kyöstilä <skyostil@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#529407}
Reviewed-on: https://chromium-review.googlesource.com/882783
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/branch-heads/3282@{#588}
Cr-Branched-From: 5fdc0fab22ce7efd32532ee989b223fa12f8171e-refs/heads/master@{#520840}
[modify] https://crrev.com/50e671d0abbcaa3b4013a229c9759b33c77daf25/gin/v8_platform.cc
[modify] https://crrev.com/50e671d0abbcaa3b4013a229c9759b33c77daf25/third_party/WebKit/LayoutTests/TestExpectations
[modify] https://crrev.com/50e671d0abbcaa3b4013a229c9759b33c77daf25/third_party/WebKit/Source/platform/TimeClamper.cpp
[modify] https://crrev.com/50e671d0abbcaa3b4013a229c9759b33c77daf25/third_party/WebKit/Source/platform/TimeClamperTest.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5e2d9bc8407f265c72ddbbcac74d8a8da09c44c2

commit 5e2d9bc8407f265c72ddbbcac74d8a8da09c44c2
Author: Nicolas Pena <npm@chromium.org>
Date: Wed Apr 25 18:21:08 2018

Move webtiming-resolution, webtiming-ssl to wpt

This CL changes the webtiming-resolution to test that resolution is
larger than 10 microseconds, instead of testing for a specific value.
This allows the test to no longer be flaky and to be moved to wpt.

The webtiming-ssl test is moved to WPT, using an https connection to
ensure that secureConnectionStart is correctly defined.

Bug:  chromium:801341 
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_mojo
Change-Id: I4d31faa08d00251098f3dc648c794d80bbcc2f22
Reviewed-on: https://chromium-review.googlesource.com/867310
Commit-Queue: Nicolás Peña Moreno <npm@chromium.org>
Reviewed-by: Robert Ma <robertma@chromium.org>
Reviewed-by: Timothy Dresser <tdresser@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553666}
[modify] https://crrev.com/5e2d9bc8407f265c72ddbbcac74d8a8da09c44c2/third_party/WebKit/LayoutTests/FlagExpectations/disable-blink-features=RootLayerScrolling
[modify] https://crrev.com/5e2d9bc8407f265c72ddbbcac74d8a8da09c44c2/third_party/WebKit/LayoutTests/TestExpectations
[add] https://crrev.com/5e2d9bc8407f265c72ddbbcac74d8a8da09c44c2/third_party/WebKit/LayoutTests/external/wpt/navigation-timing/resources/performance_attribute_sender.html
[add] https://crrev.com/5e2d9bc8407f265c72ddbbcac74d8a8da09c44c2/third_party/WebKit/LayoutTests/external/wpt/navigation-timing/test_performance_attributes.sub.html
[add] https://crrev.com/5e2d9bc8407f265c72ddbbcac74d8a8da09c44c2/third_party/WebKit/LayoutTests/external/wpt/performance-timeline/webtiming-resolution.html
[delete] https://crrev.com/62e590c5107a0fb6481e64feb676a1bd68dd2e4d/third_party/WebKit/LayoutTests/http/tests/misc/resources/webtiming-ssl.html
[delete] https://crrev.com/62e590c5107a0fb6481e64feb676a1bd68dd2e4d/third_party/WebKit/LayoutTests/http/tests/misc/webtiming-resolution-expected.txt
[delete] https://crrev.com/62e590c5107a0fb6481e64feb676a1bd68dd2e4d/third_party/WebKit/LayoutTests/http/tests/misc/webtiming-resolution.html
[delete] https://crrev.com/62e590c5107a0fb6481e64feb676a1bd68dd2e4d/third_party/WebKit/LayoutTests/http/tests/misc/webtiming-ssl-expected.txt
[delete] https://crrev.com/62e590c5107a0fb6481e64feb676a1bd68dd2e4d/third_party/WebKit/LayoutTests/http/tests/misc/webtiming-ssl.php