Summary:
Initially I removed "valgrind" from the list since it take too much
time (3+hr) compared to tsan (40 min) when the tests are run in parallel. It is
not effective to run the tests in parallel in sandcastle and tsan takes about
3hrs as well.
Adding valgrind to the list.
Test Plan: Submit this diff and watch the run
Reviewers: sdong, rven
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D53337
22ecb752db