The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f64c335bd733143a5ffe7c3432b9aa8d4f693f25

commit f64c335bd733143a5ffe7c3432b9aa8d4f693f25
Author: Liquan (Max) Gu <maxlg@chromium.org>
Date: Wed Jan 31 22:24:34 2018

[LongTaskV2] Fix flakiness in longtask-executescript test

The original test is flaky in virtual test suite.

For the virtual test, the test failed since long tasks could be present in a
slow environment. We fix it by ignoring those longtasks & attributions that are
not generated by us. Also, we tolerate the irrelevant entry lists until we
find the interesting one.

Bug:  807030 
Change-Id: I56eaa48002fd560d7fbc7b7ae1938e21ac41bf59
Reviewed-on: https://chromium-review.googlesource.com/895046
Reviewed-by: Timothy Dresser <tdresser@chromium.org>
Commit-Queue: Liquan Gu <maxlg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533443}
[modify] https://crrev.com/f64c335bd733143a5ffe7c3432b9aa8d4f693f25/third_party/WebKit/LayoutTests/TestExpectations
[delete] https://crrev.com/7437274ff84d1e2599a11454fd92df94abfba60a/third_party/WebKit/LayoutTests/http/tests/performance-timing/longtask-v2/longtask-executescript-expected.txt
[modify] https://crrev.com/f64c335bd733143a5ffe7c3432b9aa8d4f693f25/third_party/WebKit/LayoutTests/http/tests/performance-timing/longtask-v2/longtask-executescript.html