PSA: Changes to Gecko/Firefox mirrors on github

Hi, There are two officially supported mirrors of Gecko/Firefox on github: - https://github.com/mozilla/gecko-dev/ for main branches, like mozilla-central, mozilla-beta, etc. - https://github.com/mozilla/gecko-projects/ for project branches, like alder, ash, birch, etc. As of a couple hours

Intent to prototype and ship: Tab modal system prompts

Summary: A new system tab level prompt to replace (most) window prompts on Desktop. Bug: Bug 1615588 - Extend nsIPromptService to support tab modal system prompts Platform coverage: Desktop, (Android) (chrome code) Schedule: Firefox 77