Chrome Version       : 65.0.3325.209
OS Version: 10323.67.5
URLs (if applicable) :

What steps will reproduce the problem?
1. Connect a Bluetooth mouse
2. Move the mouse from areaA to areaB, all under the same window
3. Use the scroll wheel
4. Text pane that scrolls is areaA, instead of areaB.
5. After a few seconds areaB starts scrolling.

What is the expected result?
areaB scrolls

What happens instead of that?
areaA scrolls, even as the mouse pointer is over areaB.

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

UserAgentString: Mozilla/5.0 (X11; CrOS x86_64 10323.67.5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.209 Safari/537.36