Steps to reproduce the problem:
1. Open up Chrome DevTools on Android for http://paymentrequest.show/demo/
2. Start interacting with the web page in DevTools via the device screen casting.
3. Click on the buy button at the bottom of the screen.

What is the expected behavior?
The Payment Request UI should be visible on the screenshare in DevTools.

What went wrong?
It's not shown at all, you have to use the device.

Did this work before? N/A 

Chrome version: 57.0.2987.133  Channel: stable
OS Version: 
Flash Version: 

After closing payment request on the device, you CANT interact with the page with touch, the screen is locked.

This is a nasty experience now since it forces the developer to interact with both computer UI in DevTools and device UI depending on what is happening on the device.