Merge "Mutex: Note that STL is generally prefered" into nyc-dev
am: a30a626

* commit 'a30a6263d632a7d2dedc4f09c6707ab20df3fb1a':
  Mutex: Note that STL is generally prefered

Change-Id: I69eec173bf9679dc592987bd78cc8edcc81a1fbb