Tab strip/panel from vertical-tabs' layout flashes on window restore, after switching tab views

[stephendonner]

Description

Tab strip/panel from vertical-tabs' layout flashes on window restore, after switching tab views

Steps to Reproduce

1. install 1.52.61
2. launch Brave
3. load a bunch of tabs
4. context-click on a tab and choose Use Vertical Tabs
5. now, context-click again and deselect Use Vertical Tabs to return to the default mode
6. minimize Brave (but don't shut it down)
7. restore the window
8. examine the left panel

Actual result:

There's a brief flash of the previously vertical-tabs' strip/panel, on window restore.

Expected result:

No such flash.

Reproduces how often:

100%

Brave version (brave://version info)

Brave	1.52.61 Chromium: 112.0.5615.138 (Official Build) nightly (x86_64)
Revision	2258f2fcaeb07bc95c992b7ca47f0b43ead9865c-refs/branch-heads/5615@{#1282}
OS	macOS Version 11.7.6 (Build 20G1231)

Version/Channel Information:

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

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 @rebron @sangwoo108 @brave/qa-team

[stephendonner]

Screencast:

[stephendonner]

Sorry, it's hard to properly capture this without exceeding file limits pretty quickly.

[sangwoo108]

Hi, @stephendonner . Is this a Mac specific bug?

[stephendonner]

Hi, @stephendonner . Is this a Mac specific bug?

@sangwoo108 hello! Appears to be! Unable to reproduce the issue on Windows 10:

Brave	1.51.104 Chromium: 112.0.5615.165 (Official Build) beta (64-bit)
Revision	c262f36e6b1d711ee42d4fbe1343b49960593f18-refs/branch-heads/5615@{#1297}
OS	Windows 10 Version 22H2 (Build 19045.2846)

[kjozwiak]

The above requires 1.52.92 or higher for 1.52.x verification 👍

[stephendonner]

Verified PASSED using

Brave	1.52.94 Chromium: 113.0.5672.92 (Official Build) beta (x86_64)
Revision	b6f521170062a1fa8a82c33fb223b06fec566da1-refs/branch-heads/5672_63@{#10}
OS	macOS Version 11.7.6 (Build 20G1231)

Steps:

1. installed 1.52.94
2. launched Brave
3. loaded a bunch of tabs
4. context-clicked on a tab and chose Use Vertical Tabs
5. now, context-clicked again and deselected Use Vertical Tabs to return to the default mode
6. minimized Brave (but didn't shut it down)
7. restored the window
8. examined the left panel

Confirmed no tab-panel artifacts switching to and from both vertical and default (horizontal) tab modes