Fix regression caused by removing drag from URL bar element

[bsclifton]

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).

Test Plan:

Fix regression caused by removing drag from URL bar element
Fixes #5225
Unfixes (breaks) #4922 (I manually reopened)

Auditors: @bbondy

Test Plan:

1. Launch Brave and make the window smaller in size (800x600 for example)
2. make sure you can drag the window by the top area (all 6 pixels for macOS)

[bbondy]

nice, thanks.