RFR [14] JDK-8235448, code cleanup/rename in SSLContextImpl.java

[Xuelei Fan]

Hi,

Could I get the following code reviewed?
   http://cr.openjdk.java.net/~xuelei/8235448/webrev.00/
This update made a few code cleanup, including remove unnecessary 
methods, comments, etc.

Just code cleanup, no new regression test.

Thanks,
Xuelei