https://storage.googleapis.com/chromium-layout-test-archives/Linux_Tests/64629/layout-test-results/http/tests/misc/resource-timing-sizes-tags-actual.txt

--------------------
This is a testharness.js-based test.
FAIL PerformanceResourceTiming sizes tags test assert_equals: /resources/dummy.html?cb=6829933025532817 encodedBodySize expected 34 but got 0
Harness: the test ran to completion.

I can reproduce this failure in my machine by using --iterations flag.

./blink/tools/run_layout_tests.py -t Linux  --iterations=1000 --exit-after-n-failures=1 http/tests/misc/resource-timing-sizes-tags.html

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/78089c09cfcff9be98cb9fbac8da70825545f9c9

commit 78089c09cfcff9be98cb9fbac8da70825545f9c9
Author: Tsuyoshi Horo <horo@chromium.org>
Date: Fri Nov 17 02:26:37 2017

Mark resource-timing-sizes-tags.html as flaky

Bug= 786235 
TBR=ricea@chromium.org

Change-Id: I8f8540e451473ec7fdc0b4176f651e527cc0d599
Reviewed-on: https://chromium-review.googlesource.com/776253
Reviewed-by: Tsuyoshi Horo <horo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517252}
[modify] https://crrev.com/78089c09cfcff9be98cb9fbac8da70825545f9c9/third_party/WebKit/LayoutTests/TestExpectations

Reproduced. Fails about 1/2000 on my machine. Output from failed run:

This is a testharness.js-based test.
FAIL PerformanceResourceTiming sizes tags test assert_equals: /resources/dummy.html?cb=9174735982975257 encodedBodySize expected 34 but got 0
Harness: the test ran to completion.

I saw a different error on a previous run, so there may be multiple sources of instability.

Any update on this?

Ping.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/02be9389fa96ee33faf117453ddfb874cb18c542

commit 02be9389fa96ee33faf117453ddfb874cb18c542
Author: Adam Rice <ricea@chromium.org>
Date: Mon Jun 25 04:00:47 2018

Deflake resource-timing-sizes-tags.html

Reduce flakiness in layout test http/tests/misc/resource-timing-sizes-tags.html
by:
* Using the PerformanceObserver interface to reliably detect when a performance
  entry is available.
* Removing the invisible objects before completion to reduce the risk that it
  will be misdetected as a DOM test.

Other miscellaneous cleanups have been applied.

BUG= 786235 

Change-Id: Iaefbd5ee6adecad23ef39035091ba454523413f8
Reviewed-on: https://chromium-review.googlesource.com/1111893
Reviewed-by: Timothy Dresser <tdresser@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569959}
[modify] https://crrev.com/02be9389fa96ee33faf117453ddfb874cb18c542/third_party/WebKit/LayoutTests/TestExpectations
[modify] https://crrev.com/02be9389fa96ee33faf117453ddfb874cb18c542/third_party/WebKit/LayoutTests/http/tests/misc/resource-timing-sizes-tags.html