253a20fad8
When we start a resize with the docked stack divider, set the surface background to be full-screen, and use the traditional surface clipping/positioning in window manager to adjust the size. This ensures that we don't have any black holes because of asynchronicity (except at the very beginning, but this can be worked around later), and the position of the right/bottom activity is always in sync with the position of the divider. Also fix a bug in NonClientDecorView where the first request to draw was dropped (because the thread hasn't started up yet), and the main thread was waiting for it indefinitily. Bug: 24507122 Change-Id: I623bd48d5be64fac2fba45241b84f265944d200d