6025770e6b
Background: In ag/406771 we stopped deleting empty stacks in activity manager and window manager. This fixed a problem where dormant tasks were being added back to stacks later. In ag/476888 we introduced a callback to inform the ActivityView holder that the embedded task was complete. This callback was made from the new method ActivityContainer.onTaskListEmpty(). In ag/483035 onTaskListEmpty() was expanded to detach the stack of the ActivityView and also removed the stack from window manager. There was a mistake in that CL that causes it to remove any non-home stacks, not just ones in ActivityViews. That mistake left us with an empty stack in activity manager and no corresponding stack in window manager. As a result, when trying to bring back a task that used to be in this stack window manager threw up an exception. This fix limits the stacks detached by onTaskListEmpty() to those on VirtualDisplays. Fixes bug 17469145. Change-Id: I85a4452e8e85625e657d88e4cb9f366fd4026441