The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e5304693ec6db6a850d3f298ffdf9784ffec4324

commit e5304693ec6db6a850d3f298ffdf9784ffec4324
Author: Rune Lillesveen <futhark@chromium.org>
Date: Thu May 03 06:06:02 2018

Reset writing mode for media controls.

Use horizontal-tb on UA stylesheet to make sure the controls look the
same in all writing modes.

Bug:  839142 
Change-Id: I7c84afb4f1eef2cf741196b6a8639845aa72066c
Reviewed-on: https://chromium-review.googlesource.com/1041025
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555670}
[add] https://crrev.com/e5304693ec6db6a850d3f298ffdf9784ffec4324/third_party/WebKit/LayoutTests/external/wpt/html/rendering/replaced-elements/embedded-content/video-controls-vertical-writing-mode-ref.html
[add] https://crrev.com/e5304693ec6db6a850d3f298ffdf9784ffec4324/third_party/WebKit/LayoutTests/external/wpt/html/rendering/replaced-elements/embedded-content/video-controls-vertical-writing-mode.html
[modify] https://crrev.com/e5304693ec6db6a850d3f298ffdf9784ffec4324/third_party/blink/renderer/modules/media_controls/resources/legacyMediaControls.css
[modify] https://crrev.com/e5304693ec6db6a850d3f298ffdf9784ffec4324/third_party/blink/renderer/modules/media_controls/resources/modernMediaControls.css