NAME
        LockLayerRom -- lock layer structure by rom(gfx lib) code.

   SYNOPSIS
        LockLayerRom( layer )
                       a5

        void LockLayerRom( struct layer * );

   FUNCTION
        Return when the layer is locked and no other task may
        alter the cliprect structure in the layer structure.
        This call does not destroy any registers.
        This call nests so that callers in this chain will not lock
        themselves out.
        Do not have the layer locked during a call to intuition.
        There is a potential deadlock problem here, if intuition
        needs to get other locks as well.
        Having the layer locked prevents other tasks from using the
        layer library functions, most notably intuition itself. So
        be brief.
        layers.library's locklayer is identical to locklayerrom.

   INPUTS
        layer - pointer to layer structure

   RESULTS
        The layer is locked and the task can render assuming the
        ClipRects will not change out from underneath it until
        an unlocklayerrom is called.

   SEE ALSO
        unlocklayerrom() layers.library/locklayer() graphics/clip.h