Looking for a sponsor to review changes made to two unit tests under jdk/test

[Martin Buchholz]

Some very high level comments.

I think it's perfectly fine to use CountDownLatch to wait for events, as is
done in many jsr166 tests.

For the tricky problem of waiting for GC, see GcFinalization
https://code.google.com/p/guava-libraries/source/browse/guava-testlib/src/com/google/common/testing/GcFinalization.java