tree 5a8c74cf21bfb2506ac5dc9e047e15dcb0ca12f4
parent 7678dcacd8e9e7a369a66b6ade933e03617b3072
author Marie Janssen <jamuraa@google.com> 1478136715 -0700
committer Marie Janssen <jamuraa@google.com> 1481049890 -0800

Replace pthread_mutex with std::mutex

In an effort to simplify and reduce errors, replace pthread_mutexes
with std equivalents.

Test: run unit tests & manual sanity checks
Change-Id: I5c33e0b4f4c85133ae4f7415cd19372fc4c7ca1a