Send ACTION_DRAG_EXITED when the pointer moves over a non-touchable window

    void notifyLocationLw(float x, float y) {

        // Tell the affected window

        WindowState touchedWin = mDisplayContent.getTouchableWinAtPointLocked(x, y);

        if (touchedWin == null) {

            if (DEBUG_DRAG) Slog.d(TAG_WM, "No touched win at x=" + x + " y=" + y);

            return;

        }

        if (!isWindowNotified(touchedWin)) {

        if (touchedWin != null && !isWindowNotified(touchedWin)) {

            // The drag point is over a window which was not notified about a drag start.

            // Pretend it's over empty space.

            touchedWin = null;