- Removes the lock that was used to protect the audio transport object. It is now protected "by design" instead. - Removes rec/play_bytes_per_sample_ since we only support 16-bit samples. BUG=webrtc:6560 R=kwiberg@webrtc.org Review URL: https://codereview.webrtc.org/2466613002 . Cr-Commit-Position: refs/heads/master@{#14950}