hidden extensions in chromium source

[Mattches]

@DerKalle,
We’ve responded to this here:

Built in Google Tracking Extension

You can turn the extension off by disabling the Hangouts extension in brave://settings/extensions. This extension used to be required for Brave users to be able to use Google Hangouts/Meet [1, 2] but that doesn’t seem to be true any more. At this point, it looks like it’s solely used for WebRTC logging and debugging purposes, and we made sure to disable the log uploading to Google. We have disabled the extension by default and eventually will just remove it.