1894628 - Allow to select preset useragent strings in RDM

Status: NEW

(DevTools :: Responsive Design Mode, enhancement, P2)

Description

[Julian Descottes [:jdescottes]]

To make it easier to test with custom UA strings, we could have a list of built in UA strings and allow users to select them in RDM.
Instead of having a text input to write a full UA string, we would show a select listing all the builtin UA strings + a "custom" entry which would revert back to the input (or something else which allows to write a UA string).

In the long term, the list of UA string should probably be stored in remote settings, so that we can easily update them to the "current" strings used by other browsers.

It would also be nice if users could add new entries which would show up in this list.