10 RFR: 8169517: WhiteBox should provide concurrent GC phase control

[Kim Barrett]

> On Apr 11, 2017, at 12:20 PM, Dmitry Fazunenko <dmitry.fazunenko at oracle.com> wrote:
> 
> Kim,
> 
> The tests you provided will work, but they are really hard to understand.
> To demonstrate what I meant suggesting improvement I converted them:
>   http://cr.openjdk.java.net/~dfazunen/8169517/webrev.00/

This is pretty much what I was trying to avoid doing.

While I still (mildly) prefer the approach I'd taken, I do see good
points to this.

Since you seem to feel strongly enough about it to actually implement
the changes, I'm willing to go along.

I should have a new webrev tonight or tomorrow.