base

Fix issue #2594388: WallpaperService doesn't always call onSurfaceDestroyed()

Take care of the window manager destroying a surface, to report to the
app that it has been destroyed.  Make sure to perform a traversal when
becoming visible to re-create the surface if needed.

Change-Id: If3bc05e0106f90d4c3bad2d7575212667680fbc8