In r170036, I made it so that setRenderTreeSize would remove the snapshot even if m_snapshotRemovalTargetRenderTreeSize wasn't set, so that we would still wait until the first relevant layer tree commit to remove the snapshot. However, this also removed the only guard that ensured that we only removed the snapshot after the swipe was complete; now, any layer tree commit that comes in *during* the swipe will cause the snapshot to be removed. Oops!
Let's make the old behavior more explicit.
Created attachment 233581 [details]
Comment on attachment 233581 [details]