Don't crash when QSGViewSection has a null parent.
Don't crash when QSGViewSection has a null parent.

This is required to make qmlplugindump work.

Change-Id: I041adde3e48759f9c3ae166c887a26ccb8f264f9
Reviewed-on: http://codereview.qt-project.org/5800
Reviewed-by: Roberto Raggi <5b38c5be65ca2d75b92c40e91029e90f276fd4fe@nokia.com>

jfaust/qtdeclarative,mgrunditz/qtdeclarative-2d,corngood/qtdeclarative,qmlc/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,jfaust/qtdeclarative,corngood/qtdeclarative,corngood/qtdeclarative,crobertd/qtdeclarative,matthewvogt/qtdeclarative,corngood/qtdeclarative,qmlc/qtdeclarative,matthewvogt/qtdeclarative,jfaust/qtdeclarative,crobertd/qtdeclarative,crobertd/qtdeclarative,mgrunditz/qtdeclarative-2d,crobertd/qtdeclarative,jfaust/qtdeclarative,mgrunditz/qtdeclarative-2d,corngood/qtdeclarative,qmlc/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,jfaust/qtdeclarative,crobertd/qtdeclarative,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,jfaust/qtdeclarative,jfaust/qtdeclarative,qmlc/qtdeclarative,crobertd/qtdeclarative,corngood/qtdeclarative,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,matthewvogt/qtdeclarative,mgrunditz/qtdeclarative-2d,crobertd/qtdeclarative,mgrunditz/qtdeclarative-2d,corngood/qtdeclarative