Whitelist DuckDuckGo for Brave UA

[bbondy]

Duck Duck Go has a good use case to provide special instructions for better privacy for Brave, and wants to have Brave in the UA.

We do this also for adobe which needs special instructions on desktop.
https://github.com/brave/browser-laptop/blob/master/js/data/siteHacks.js#L64

You should still keep Chrome in the UA, but make it like that link above shows, only for duckduckgo.com.

[bsclifton]

Steps to test manually (I ran and verified it works fine)

1. Launch Brave and visit https://duckduckgo.com
2. Open the developer tools (F12 or shift + option + i)
3. Force reload the page (shift + cmd + R or shift + ctrl + R)
4. Inspect the network tab for the duckduckgo.com resource
5. Under request headers, you should see the user agent:
   "user-agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Brave Chrome/59.0.3071.115 Safari/537.36"

[bbondy]

For testing open up the content dev tools and make sure the User Agent (shown on bottom right corner CONTAINS "Brave" in the string only for adobe.com and for duckduckgo.com

[srirambv]

[LaurenWags]

adobe.com and duckduckgo.com

[bbondy]

lgtm, third test would be making sure a different site doesn't have the word Brave in it.

[LaurenWags]

agreed, @bbondy - checked youtube.com also:

[bbraithwaite]

Thank you very much for adding this! I'm a dev @ DDG and was wondering if there is a way to extend this functionality to whitelist the useragent further so that it can be accessed via JavaScript e.g. navigator.userAgent?

Am happy to help out with making the change if you want to point me in the right direction.

[bsclifton]

@bbraithwaite good question- maybe we can consider a similar filtering based work-around:
cc: @diracdeltas

[bbraithwaite]

@bsclifton Just following up here to ask if this change will be possible in the future? Thank you.

[bsclifton]

@bbraithwaite thanks for following up! Would you be able to create a new issue to track that work? I think it's do-able and would be a nice addition 😄