Google Chrome	65.0.3322.0 (Official Build) dev (64-bit)
Firmware Version	Google_Lulu.6301.136.57

Steps to repro:

# Navigate to www.google.com or the NTP
# Linear navigate rapidly using search + arrow keys
Works as expected, old speech is interrupted by new speech to keep up with the content currently in the focus ring
# Tab rapidly around the page (press tab quickly)
# Observe the focus ring compared to the words spoken
Expected: just like linear navigation, new speech interrupts old speech to keep up with the focus ring
Actual: ChromeVox is still speaking content from many tabs ago. If I stop tabbing, it will eventually catch up to where I am not but it's not reflecting what's really focused now.