Navigating back-and-forth between regular and DRM-based videos on YouTube triggers Skip-Ad overlay

[stephendonner]

Description

Navigating back-and-forth between regular and DRM-based videos on YouTube triggers Skip-Ad overlay

Steps to Reproduce

1. clean profile, launch Brave
2. load youtube.com
3. log in with a non-Premium account
4. load a video (doesn't seem to matter)
5. search for The Good, The Bad and the Ugly (or any Free with ads video)
6. play the above video, and click on the I acknowledge...mature-content disclaimer, if it exists
7. install Widevine (I already had it installed in the screencast below)
8. let the video play a bit
9. click the Back button
10. now, click Forward

Actual result:

Skip-ads overlay appears

Expected result:

Video plays, with no Skip-ads overlay

Reproduces how often:

100% (YAY - it's been elusive, prior to these steps)

Brave version (brave://version info)

Brave	1.23.22 Chromium: 89.0.4389.72 (Official Build) nightly (x86_64)
Revision	3f345f156bfd157bd1bea06310e55f3fb2490359-refs/branch-heads/4389@{#1393}
OS	macOS Version 11.2.2 (Build 20D80)

Version/Channel Information:

• Can you reproduce this issue with the current release? yes
• Can you reproduce this issue with the beta channel? yes
• Can you reproduce this issue with the nightly channel? yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
• Does the issue resolve itself when disabling Brave Rewards?
• Is the issue reproducible on the latest version of Chrome?

Miscellaneous Information:

cc @SergeyZhukovsky @antonok-edm @ryanbr

[stephendonner]

As @spylogsster noted on Slack, I think this was an incomplete backout state - I can no longer reproduce this with

Brave	1.23.23 Chromium: 89.0.4389.72 (Official Build) nightly (x86_64)
Revision	3f345f156bfd157bd1bea06310e55f3fb2490359-refs/branch-heads/4389@{#1393}
OS	macOS Version 11.2.3 (Build 20D91)