This information source from the following url:
http://peter.sh/experiments/chromium-command-line-switches/
--use-fake-device-for-media-stream
--use-fake-ui-for-media-stream
--use-fake-ui-for-media-stream
See my bash alias for an example...
NOTE: No audio as far as I can tell.
--enable-logging --v=1 --vmodule=*source*/talk/*=3
# initialise the chrome alias
alias chrome="rm -rf $HOME/.config/chrome-test && google-chrome --console --no-first-run --user-data-dir=$HOME/.config/chrome-test --use-fake-device-for-media-stream --use-file-for-fake-video-capture=/home/doehlman/testvideo.y4m --enable-logging --v=1 --vmodule=*third_party/libjingle/*=3,*=0"
/talk/app/webrtc/mediaconstraintsinterface.h
Starting firefox with logging (for data channels and sctp in this case):
NSPR_LOG_MODULES=datachannel:5,sctp:5 /opt/browsers/firefox/stable/firefox http://localhost:9966/