RFR: 8065233: Remove Policy provider code that synchronizes on identityPolicyEntries List

[Sean Mullan]

This is the second in a series of fixes for JEP 232 (Improve Secure 
Application Performance) [1].

webrev: http://cr.openjdk.java.net/~mullan/webrevs/8065233/webrev.00/
bug: https://bugs.openjdk.java.net/browse/JDK-8065233

This fix removes some obsolete synchronization code from the Policy 
implementation. This results in a slight improvement (about 2-4%) in the 
throughput of the Policy.getPermissions method. The bug contains a 
performance chart with more details.

Thanks,
Sean

[1] http://openjdk.java.net/jeps/232