am 669ec3a6: Merge change 1747 into donut

Merge commit '669ec3a6e47248fee0a3a0f4877b46875eb42140'

* commit '669ec3a6e47248fee0a3a0f4877b46875eb42140':
  Fixes #1846038. The dirty region can sometimes be modified by SurfaceFlinger. When this happens, force the view hierarchy to ignore the dirty flags.