The animation that runs when the NotificationPanel appears used to start, then pause for a long time as the window/surface/layer was created, then by the time it started to be visible, the animation was over. This new approach delays starting the animation until the layer has been drawn, so the animation can actually run a few frames after that before finishing. Change-Id: I998f01fd48cb762178021ad99e2b919b58a1ef3f