Google Chrome	71.0.3558.0 (Official Build) dev (64-bit)
Firmware Version	Google_Caroline.7820.384.0

Steps to reproduce:
# Open either magnifier, docked or full screen, using settings > Manage Accessibility Features or by using ctrl + search + d or ctrl + search + m
# Download a .docx, .xlsx, or .pptx file (I created these by using "Download as" from Google Docs/Sheets/Slides)
# Open it locally in Chrome OS out of files, opening the Office Editing extension.
# Move the keyboard focus either by tabbing around in the content or by using a keyboard shortcut such as alt + f for file
Expected: magnifier follows keyboard focus
Actual: magnifier remains with mouse focus, sometimes moves such as if tabbing many rows to the right but still not in line with keyboard focus