Correct comment

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1515663 13f79535-47bb-0310-9956-ffa450edef68
Rework r1515612
Avoid ISE when session is closed.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1515664 13f79535-47bb-0310-9956-ffa450edef68
Fix unit test failure observed on command line on Windows.
SecureRandom took took long to initialise causing test to fail.
Initialize a SecureRandom instance before running the test.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1515669 13f79535-47bb-0310-9956-ffa450edef68