When shutting down an application on Windows Phone the SceneGraph tries
to create an offscreen surface to render into. If there is no offscreen
surface available, it creates a new native window and tries to hide it.
As the native event loop is about to shut down, creation fails and
exceptions are raised. Instead we create a vanilla
QPlatformOffscreenSurface. The SceneGraph recognizes it as such and can
handle a proper cleanup on its own.
Furthermore removing the suspend/resume handler in the destructor of
QWinRTIntegration fails for Windows Phone as the application object
itself does not accept this anymore. Hence skip this part for this
platform.
Task-number: QTBUG-49310
Change-Id: I02acdd5a635ef0b9d6ef8199376537b8f0f1a8fb
Reviewed-by: Oliver Wolff <oliver.wolff@theqtcompany.com>
becbffe291