The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/39dbf2828b01d4c06ae3af8f096708d59a8f5d60

commit 39dbf2828b01d4c06ae3af8f096708d59a8f5d60
Author: Tommy Steimel <steimel@chromium.org>
Date: Fri Mar 16 20:47:43 2018

Increase timeline height from 2px to 4px

This CL modifies the modern media controls CSS to have a larger
timeline in order to match the new mocks.

Bug:  814958 ,  817303 
Change-Id: I049dbc2042d5af4b45d799ddd9f14881a6f0cc03
Reviewed-on: https://chromium-review.googlesource.com/963840
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Commit-Queue: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543818}
[modify] https://crrev.com/39dbf2828b01d4c06ae3af8f096708d59a8f5d60/third_party/WebKit/Source/modules/media_controls/resources/modernMediaControls.css
[modify] https://crrev.com/39dbf2828b01d4c06ae3af8f096708d59a8f5d60/third_party/WebKit/Source/modules/media_controls/resources/modernMediaControls_loading.css