"UI tour" doesn't work well with hidden mode bar

1. Select "View" -> "Modes" -> "Hidden" from the menu.
2. Select "Help" -> "UI Tour" from the menu.
   The tour highlights an area where there's nothing to see:
   
3. Proceed to step 2 of the tour.
4. Resize the window
   The highlight does not even follow the size of the window:
   

Possible improvements I see:

• Temporarily show the mode bar during the tour
• Start the tour with instructions how to show the mode bar
  This might also help users who accidentally hid the bar
• Disable the UI tour when the mode bar is hidden
  Assuming users knew what they did