Comment 1 for bug 1370975

It is already possible to override the user agent for a given webapp. The process is bit more involving than adding a command line argument though:

- you need a webapp-properties.json file local to your webapp click package OR a manifesty.json file a unity-webapp-* folder,
- such a json file must have the listed properties:

{
    "name": "<yourwebapp>",
    "homepage": "<homepageurl>",
    "domain": "<domain>",
    "includes": []
}

- you must add a "user-agent-override" property to the file above with the proper user agent,
- you must also add --webappModelSearchPath=. to your command line,

Since all this is a bit cumbersome, I added a branch here that simplifies the process.