I'm preparing adding support for Java VideoFrames in AndroidVideoTrackSource. I split out small unrelated clean-ups into this CL in order to make the big CL more focused. Bug: webrtc:7749 Change-Id: Ib261ab8eb055898b39307d4e78935bf60d323820 Reviewed-on: https://chromium-review.googlesource.com/539638 Reviewed-by: Sami Kalliomäki <sakal@webrtc.org> Commit-Queue: Magnus Jedvert <magjed@webrtc.org> Cr-Commit-Position: refs/heads/master@{#18660}