OSK sometimes does not get dismissed when unfocusing an app

[Michał Sawicz]

$ system-image-cli -i
current build number: 114
device name: krillin
channel: ubuntu-touch/rc-proposed/bq-aquaris.en
last update: 2015-09-02 10:40:50
version version: 114
version ubuntu: 20150902
version device: 20150821-736d127
version custom: 20150821-887-33-32-vivid

Steps:
- open messaging
- focus the search field
- press power button to suspend
- press power button to wake

Expected:
- OSK is dismissed

Current:
- OSK sometimes visible over the greeter and passcode entry (see attached screenshots).

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: unity8 8.11+15.04.20150831.2-0ubuntu1 [origin: LP-PPA-ci-train-ppa-service-stable-phone-overlay]
Uname: Linux 3.4.67 armv7l
ApportVersion: 2.17.2-0ubuntu1.3touch1
Architecture: armhf
Date: Thu Sep 3 09:49:03 2015
InstallationDate: Installed on 2015-09-02 (1 days ago)
InstallationMedia: Ubuntu 15.04 - armhf (20150902-020305)
SourcePackage: unity8
UpgradeStatus: No upgrade log present (probably fresh install)