It seems at the end of the animation, sometimes we will come to think we have focus, before we have properly updated mStackId. This in-and-of itself seems like somewhat of an issue...but I'm not inclined to dig too deeply at the moment. For now just ensure a static shadow size in the pinned stack. Bug: 37425446 Test: Manual Change-Id: I379f7a6de51670c90eacb52a5be5e17784be8ac5