UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.65 Safari/537.36

Steps to reproduce the problem:
1. Start unclutter.
2. Visit chromium window.
3. Wait for mouse pointer to disappear.
4. Use mouse wheel.

What is the expected behavior?
The HTML page should be scrolled.

What went wrong?
Scrolling does not work.

Did this work before? Yes In previous Ubuntu 14.04 Chromium (approx. from Feb 2016)

Chrome version: 39.0.2171.65  Channel: stable
OS Version: 3.13.0-83-generic
Flash Version: 

Using two-finger scrolling on the touchpad is euqally affected.  Other applications are not affected, only chromium.