ComboBox autotest fails on Linux

ComboBox auto tests have started constantly failing in the latest stable. The problem is that ComboBox does not get active focus as expected.

• http://testresults.qt-project.org/ci/QtQuickControls_stable_Integration/build_00550/linux-g++_shadow-build_Ubuntu_11.10_x86/log.txt.gz
• http://testresults.qt-project.org/ci/QtQuickControls_stable_Integration/build_00552/linux-g++_no-widgets_Ubuntu_12.04_x64/log.txt.gz
• ...

qtquickcontrols is a reverse dependency to qtdeclarative, so it's currently blocking qtdeclarative integration as well:

• http://testresults.qt-project.org/ci/QtDeclarative_stable_Integration/build_02071/revdep-qtquickcontrols_linux-g++_shadow-build_Ubuntu_11.10_x86/log.txt.gz
• http://testresults.qt-project.org/ci/QtDeclarative_stable_Integration/build_02073/revdep-qtquickcontrols_linux-g++_developer-build_qtnamespace_qtlibinfix_Ubuntu_12.04_x64/log.txt.gz
• ...

I have tracked down the problem to https://codereview.qt-project.org/#change,82587.