The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3afe31c1ce2fdf0b7981d3a7e73d2031dbd2d02c

commit 3afe31c1ce2fdf0b7981d3a7e73d2031dbd2d02c
Author: Yutaka Hirano <yhirano@chromium.org>
Date: Tue Oct 31 13:41:48 2017

Mark external/wpt/beacon/headers/header-content-type.html as Slow

Bug:  779965 , 626703,  729849 
Change-Id: I795f9a2a22b886bc70301452adbab626ab324b99
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_mojo
Reviewed-on: https://chromium-review.googlesource.com/746487
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512820}
[modify] https://crrev.com/3afe31c1ce2fdf0b7981d3a7e73d2031dbd2d02c/third_party/WebKit/LayoutTests/FlagExpectations/enable-features=NetworkService
[modify] https://crrev.com/3afe31c1ce2fdf0b7981d3a7e73d2031dbd2d02c/third_party/WebKit/LayoutTests/SlowTests
[modify] https://crrev.com/3afe31c1ce2fdf0b7981d3a7e73d2031dbd2d02c/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1c0d3de1b43aecd849594c5366c3e5335c763acc

commit 1c0d3de1b43aecd849594c5366c3e5335c763acc
Author: Yutaka Hirano <yhirano@chromium.org>
Date: Mon Feb 19 16:44:04 2018

Fix wpt/beacon/headers/header-content-type.html slowness

This CL uses ResourceTiming API to speed up the test cases while
avoiding flakiness.

Bug:  779965 
Change-Id: I40dc2fae470df296c87c12e432fc7fc7644cc40a
Reviewed-on: https://chromium-review.googlesource.com/923625
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537664}
[modify] https://crrev.com/1c0d3de1b43aecd849594c5366c3e5335c763acc/third_party/WebKit/LayoutTests/SlowTests
[modify] https://crrev.com/1c0d3de1b43aecd849594c5366c3e5335c763acc/third_party/WebKit/LayoutTests/external/wpt/beacon/headers/header-content-type.html