just a lil tweakaroonie to make recents draw with hardware acceleration

Change-Id: I179733ba231af1b45f5608d47cc00a4096643538
Fixed incorrect calculation of dirty invalidation area

Padding was already taken into consideration before calling
invalidateDrawable in ProgressBar.

Change-Id: Id7f23bd15bb19e2294c07adb2acb397100ea97e8