Bug: east/west travel on keyboard is interrupted when VoiceOver Live Region active

[nwisehart]

Steps to reproduce:

• go to /a11y-map/index.html
• navigate with keyboard to area over pop-ups
  • I went 7 arrows west, then 5 arrows south from the starting position to sit over a region of three pop-ups
• turn on VoiceOver for OS X (cmd-f5)
• try to rapidly travel east with keyboard (right arrow)

Expected result:

• Travels east

Context:
Initial assumption is that the ARIA Live Region is taking priority over the JS to move the map east and west. This doesn't happen with north and south though.

Supporting Info:

• Google Chrome Version 68.0.3440.106
• OS X High Sierra
• localhost..././a11y-map/index.html