Caption buttons are not shown when in fullscreen mode (Windows)

[bsclifton]

Did you search for similar issues before submitting this one?
Yes

Describe the issue you encountered:
Introduced with #3854, I had hidden the caption buttons based on verbal feedback from folks.

Expected behavior:
Caption buttons should always show when fullscreen (else, there is not an easy way to exit)

• Platform (Win7, 8, 10? macOS? Linux distro?):
  All Windows
• Brave Version:
  0.12.2 and newer
• Steps to reproduce:
  1. Launch Brave
  2. Hit F11 to go full screen
  3. Notice you can't exit (no caption buttons)
• Screenshot if needed:
• Any related issues:

[luixxiul]

I thought the max button would exit the fullscreen mode (min and exit buttons work). Should it not so?