brandtr c287c80781 Remove source file writer from VideoProcessor.
It serves a very limited purpose: converting from the input YUV
file to an output Y4M file. The experimenter can do this manually,
if this is of interest. (It is generally not.)

BUG=webrtc:6634

Review-Url: https://codereview.webrtc.org/2993063002
Cr-Commit-Position: refs/heads/master@{#19257}
2017-08-07 15:30:43 +00:00
..
2017-07-12 23:11:09 +00:00