RFR(XS) 8191924: Adjust DelegatingClassLoader's metadata space sizing algorithm

[Zhengyu Gu]

Hi Thomas,

> 
> 
> Looks fine. Good results :)
> 

Thanks for the review.

> Should we assert the Metaspace lock somewhere?
> 
> I think we should add aggregated counters in SpaceManager by chunk type 
> to not having to walk-and-count each time, but that is for another day. 
> I have a patch like that somewhere in my backlog.

Let's do a round of cleanup separately. I do believe we can remove 
xxx_slow() version.

-Zhengyu


> 
> ..Thomas
>