The test program audioproc_f does not call the stream_analog_level
method. This should be done do
1) Ensure that proper log output is produced when reproducing a call.
2) Ensure that this method is properly tested.
3) Ensure that the correct side-effects are triggered (this method
is not const).
BUG=webrtc:6564
Review-Url: https://codereview.webrtc.org/2449043008
Cr-Commit-Position: refs/heads/master@{#14817}
f005a00094