Detect displays in Displays does not update or show all resolutions

[Vaclav Petras]

The Detect displays button in 16.04 does not update the list of resolutions and ratios.

1. Connect laptop to external screen using VGA. Screen is 16:9.
2. Suspend the laptop.
3. Connect another screen with ratio 16:10.
4. Wake up from suspend.
5. Open Displays.
6. Press Detect displays.

The list of resolutions and ratios should be now updated but it is not. To use the actual screen ratio I need to unplug and plug the VGA cable.

If I recall correctly, before 16.04 it was enough just to start Displays and the right resolution/ratio was detected and used.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: unity-control-center 15.04.0+16.04.20160705-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-59.80-generic 4.4.35
Uname: Linux 4.4.0-59-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.4
Architecture: amd64
CurrentDesktop: Unity
Date: Tue Jan 31 09:32:25 2017
SourcePackage: unity-control-center
UpgradeStatus: Upgraded to xenial on 2016-12-23 (38 days ago)