Fullscreen toolbar moves window down on Mac

[correcthorsebatterystaple]

Description

The toolbar that appears at the top of the screen when in fullscreen mode doesn't overlay the window like other popular browser but rather shifts the whole window down by the height of the toolbar

Steps to Reproduce

1. Open brave browser
2. Fullscreen the browser
3. Move cursor to the top of the screen

Actual result:

Expected result:

The toolbar should overlay over the window instead of shift it down

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Brave | 1.31.88 Chromium: 95.0.4638.69 (Official Build) (arm64)
Revision | 6a1600ed572fedecd573b6c2b90a22fe6392a410-refs/branch-heads/4638@{#984}
OS | macOS Version 11.6 (Build 20G165)

Version/Channel Information:

• Can you reproduce this issue with the current release?
• Yes
• Can you reproduce this issue with the beta channel?
• Don't know
• Can you reproduce this issue with the nightly channel?
• Don't Know

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
• No
• Does the issue resolve itself when disabling Brave Rewards?
• No
• Is the issue reproducible on the latest version of Chrome?
• Yes

Miscellaneous Information:

[rebron]

Related to: #19242 but different. This one is a feature request to do an overlay of the hover and not shift contents down.

[freebrowser1]

Here same issue on an Intel Mac.
It appears that 'full screen' is just fake.