3a5c721072
An accessibility service may register to observe the interactive windows on the primary display. These windows are the one that has input focus and ones a sighted user can touch. It is sometimes beneficial for an accessibility service to overlay a window to intercept user interaction and based on that introspect and perform an action on the windows that are on the screen. This is problematic as overlaying a full screen window that is touchable prevents the accessibility service to introspect the content under this window. This change adds a special type of window that only an accessibility service can place which does not affect what an accessibility service can "see" on the screen. Hence, even putting such a window full screen the service will be able to interact with the other interactive windows it covers. Change-Id: I053ccc3a5c6360a98dc40bdb172b54dab35d8b31