RFR (trivial) 8197772: metaspace uses global operator new/delete for gtest testing

[Kim Barrett]

> On Feb 13, 2018, at 6:23 PM, coleen.phillimore at oracle.com wrote:
> 
> Summary: Inherit ChunkManagerReturnTestImpl from CHeapObj
> 
> open webrev at http://cr.openjdk.java.net/~coleenp/8197772.01/webrev
> bug link https://bugs.openjdk.java.net/browse/JDK-8197772
> 
> Tested with gtest that uses it.
> 
> Thanks,
> Coleen

Looks good, and trivial.