custom ads are misplaced when switching monitors

[rebron]

Description

When switching from desktop monitor to laptop monitor, custom ad notifications are placed off screen and cutoff.

Steps to Reproduce

1. Use Brave Nightly on a laptop with connected monitor. Browse normally and wait for custom ad to appear and should be fully visible on right corner of screen.
2. Disconnect laptop from connected monitor.
3. Using Brave via laptop monitor, wait for custom ad to appear and notice that custom ad is off the screen.

Expected result:

Custom ad should be fully visible on the top right of the screen.

Reproduces how often:

Intermittent

Brave version (brave://version info)

Brave	1.27.13 Chromium: 91.0.4472.70 (Official Build) nightly (arm64)
Revision	fe095368270a32c92959403754bf6fd357dd9953-refs/branch-heads/4472@{#1172}
OS	macOS Version 11.3 (Build 20E232)

Version/Channel Information:

• Can you reproduce this issue with the current release? n/a
• Can you reproduce this issue with the beta channel? n/a
• Can you reproduce this issue with the nightly channel? Yes

Other Additional Information:

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

Miscellaneous Information:

[rebron]

Closing. Can't reproduce on current builds in beta or nightly.

Brave	1.26.43 Chromium: 91.0.4472.77 (Official Build) beta (arm64)
Revision	1cecd5c8a856bc2a5adda436e7b84d8d21b339b6-refs/branch-heads/4472@{#1246}
OS	macOS Version 11.3 (Build 20E232)

Brave	1.27.24 Chromium: 91.0.4472.77 (Official Build) nightly (arm64)
Revision	1cecd5c8a856bc2a5adda436e7b84d8d21b339b6-refs/branch-heads/4472@{#1246}
OS	macOS Version 11.3 (Build 20E232)