Merge "Fix hidden EmptyShadeView" into sc-dev

        // After the shelf has updated its yTranslation, explicitly set alpha=0 for view below shelf

        // to skip rendering them in the hardware layer. We do not set them invisible because that

        // runs invalidate & onDraw when these views return onscreen, which is more expensive.

        if (shelf.getViewState().hidden) {

            // When the shelf is hidden, it won't clip views, so we don't hide rows

            return;

        }

        final float shelfTop = shelf.getViewState().yTranslation;

        for (ExpandableView view : algorithmState.visibleChildren) {

            if (view instanceof ExpandableNotificationRow) {

                ExpandableNotificationRow row = (ExpandableNotificationRow) view;

                if (row.isHeadsUp() || row.isHeadsUpAnimatingAway()) {

                    continue;

                }

            }

            final float viewTop = view.getViewState().yTranslation;

            if (viewTop >= shelfTop) {

                view.getViewState().alpha = 0;