RFR: 8065213 Specify and implement PlatformMBeanProvider for looking for all platform MBeans

[shanliang]

Hi,

Hope this is last time :)
    http://cr.openjdk.java.net/~sjiang/JDK-8065213/02/

1)
Mandy Chung wrote:
> You may want to consider using limited doPrivileged (that can be done 
> in the second phase).
Done as in ManagementFactory:
 878             // get all providers
 879             List<PlatformMBeanProvider> providers
 880                 = 
AccessController.doPrivileged((PrivilegedAction<List<PlatformMBeanProvider>>) 
() -> {
 881                     List<PlatformMBeanProvider> all = new 
ArrayList<>();
 882                     for (PlatformMBeanProvider provider : 
ServiceLoader.loadInstalled(PlatformMBeanProvider.class)) {
 883                         all.add(provider);
 884                     }
 885                     all.add(new DefaultPlatformMBeanProvider());
 886                     return all;
 887                 },
 888                 null,
 889                 new FilePermission("<<ALL FILES>>", "read"),
 890                 new 
RuntimePermission("sun.management.spi.PlatformMBeanProvider"));

2)
The modification to Flag is removed, we get another solution to know 
whether commercial feature is enabled.

3) some mis minors modifications.

Thanks,
Shanliang