The purpose is to be able to easier test and find differences between the path when capturing to textures or byte buffers. This require https://codereview.webrtc.org/1403713002/ to work. BUG=webrtc:4993 R=magjed@webrtc.org TBR=glaznew@webrtc.org Review URL: https://codereview.webrtc.org/1452423003 . Cr-Commit-Position: refs/heads/master@{#10766}