Reduce frame latency for WP8

This brings to WP8 the same behavior we have for other Win8/DX targets.
Revert "Reduce frame latency for WP8"

This reverts commit 9f8a1a15b3d089d4eabb5993e6244546d6b951a9.
Reduce frame latency for WP8

Move code to UpdateDevice(...) which is in the execution path of both
DrawingSurface & DrawingSurfaceBackgroundGrid.
Merge pull request #2210 from nkast/tnc_WP8ReduceFrameLatency

Reduce frame latency for WP8