* Enables WebRTC (if currently disabled)
* Turns on the setting media.navigator.permission.disabled, which allows all WebRTC connections without prompting
* (Version 1.4.0+ only) Checks the status of OpenH264; if it's enabled but not installed, the user will be asked if they want to install or disable it
SeaMonkey does not have a permissions dialog to let the user select a camera and microphone (see bug 956854), so using media.navigator.permission.disabled to override the dialog is the only way to enable WebRTC support.
Of course, leaving this setting on is insecure, since any web site that's open will be able to get access to your microphone, camera, and screen! So be sure to only turn it on when you need to use WebRTC, and turn it off once you're done with it.
See https://github.com/IsaacSchemm/webrtc-permissions-ui-toggle for more information.