Chrome Version: M65)
OS: Android

What steps will reproduce the problem?
(1) Scroll down so the omnibar disappears
(2) Long-press text very close to the top of the phone screen (so the
    floating action mode is positioned under the selection).

What is the expected result?
The floating action mode should be positioned below the handles.

What happens instead?
The floating menu is positioned over the handles (overlaps them).

The problem is that the long-press drag selector is active while the
long-press and initial selection happens. This means the handles are
hidden so when the menu is positioned as if the handles weren't there.
There are multiple possible solutions. One is to refactor the 
long-press drag selector crbug.com/807422. Another is to call
|TouchSelectionControllerClient::OnSelectionEvent()| after the
long-press drag selector is done instead of before.