In the Payment Request flow, the client page is expected to at some point call the PaymentResponse.complete() method which should trigger the PR UI to close.
This succeeds normally. But if the page calls setTimeout and puts the call to complete() inside the timeout, then the timeout doesn't fire and thus the UI doesn't close. Unless you subsequently switch the device to landscape orientation, then the timeout code runs, the complete() method is called, and the PR UI closes.
Note: this issue only occurs on a real device, not in the simulator.
Comment 1 by bugdroid1@chromium.org
, Jan 18 2017