After https://codereview.webrtc.org/1827263002, audio devices are no longer (ever) initialized if they return true from RecordingIsInitialized. Since this was left as "return true;" for file_audio_device, the recording buffer was never set up correctly, and the audio buffer would assert when called (in debug) and FileAudioDevice would cause memory corruption (in release). BUG= Review-Url: https://codereview.webrtc.org/2116003003 Cr-Commit-Position: refs/heads/master@{#13489}