commit 4e103290aaecba63db670aead636ee8733e10e35
author Majid Valipour <majidvp@chromium.org> Tue May 29 15:22:53 2018
committer Commit Bot <commit-bot@chromium.org> Tue May 29 15:22:53 2018
tree 06e1f5937be252cbb33ac395414907cbdfbed241
parent 63ca6994257dcff81f5381ed55aa46b9a7976081

Fix flakiness in hr-timestamp/input-events.html test

Update the test to expect the difference between expected
unclamped time with observed time to be at most 200us instead of 100us.


A recent change [1] made it so that the clamping can lead to up to 200us
of adjustment for when we are computing a time values that is relative
to time origin. The new logic, first clamps both the time origin and time value
and then computes their delta while the old logic computed the delta first and
then clamped it once.

## simplified old logic
double clamped_time_in_seconds = ClampTimeResolution(monotonic_time - time_origin);

## simplified new logic

double clamped_time_in_seconds =
      ClampTimeResolution(TimeTicksInSeconds(monotonic_time)) -
      ClampTimeResolution(TimeTicksInSeconds(time_origin));


Flakiness dashboard link: https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=webkit_layout_tests&tests=fast%2Fevents%2Fhr-timestamp

[1] https://chromium-review.googlesource.com/c/chromium/src/+/849993/4/third_party/WebKit/Source/core/timing/PerformanceBase.cpp

TEST= locally ran the test 1000 times which all passed. run-webkit-tests --repeat-each=1000  fast/events/hr-timestamp/input-events.html

Bug: 846750, 810437
Change-Id: I69547484838c3b21bc3c15441baec287db0f5e8e
Reviewed-on: https://chromium-review.googlesource.com/1072466
Commit-Queue: Majid Valipour <majidvp@chromium.org>
Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562430}