Chrome Version: M66
OS: Linux and Android (probably also CrOS and Win but haven't tried)
What steps will reproduce the problem?
(1) Go to textarea.org and type "hello" on the first line and make  
    a few new lines after it. 
(2) Long-press "hello" to get the touch handles to show up
(3) Drag the end handle down to the newlines. So you highlight them

What is the expected result?
The end handle should follow the expanded selection

What happens instead?
The handle is placed on the top left corner of the page.

Bisecting led me to: https://chromium-review.googlesource.com/c/chromium/src/+/875842