Chrome Version       : 66.0.3359.139 (Official Build) (64-bit) (cohort: Stable)
Revision	a020eddf0d85fe84d4a6787b304f50aafb670969-refs/branch-heads/3359@{#767}
URLs (if applicable) : n/a
Other browsers tested:
  Add OK or FAIL, along with the version, after other browsers where you
have tested this issue:
     Safari: n/a
    Firefox: n/a
       Edge: n/a

What steps will reproduce the problem?
(1) click on the screen area within about 1" above the taskbar and in the right 1/5 of the screen -- or, occasionally, on the right portion of the taskbar itself.  Any app can be occupying that portion of the screen.
(2)
(3)

What is the expected result?

The expected result is the normal operation of whatever app is being clicked on;  e.g., changing zoom level on Open Office Impress.

What happens instead?

Instead, Chrome pops up.  Almost always it plays a YouTube video (usually of Lady Ada, because I'm subscribed to Adafruit Industries' periodic videos).

Please provide any additional information below. Attach a screenshot if
possible.

I'm sorry, that's all I have for you.  But it has happened dozens of times.