Categories: News

These Weeks in Firefox: Issue 16


  • about:addons now has a legacy tag to show when an extension is not a WebExtension and now specifically tags WebExtensions as compatible on Firefox 57!
  • The Activity Stream Test Pilot now shows recommended stories from Pocket, and you can  try the first bits of the Activity Stream integration in Firefox on Nightly by switching the pref browser.newtabpage.activity-stream.enabled

The new about:newtab featuring Activity Stream!

Friends of the Firefox team

(Give a shoutout/thanks to people for helping fix and test bugs. Introductions)

Project Updates


Electrolysis (e10s)

  • gabor turned on the pre-allocated process manager, which should improve the perceived performance of opening tabs and windows in new processes
  • mconley is currently fixing a regression in the tab switch spinner metric
  • e10s-multi A/B test is currently underway on Beta
  • e10s-a11y support still targeted for Firefox 55

Firefox Core Engineering

  • Shield Study defaulting Flash to click-to-play (Plugin Safety) has begun on Release 53 and will run through June 15.

Form Autofill



  • We are working on deterministic perf tests for sync reflows and files loaded too early during startup
    • Sync layout and style flush tests will be in browser/base/content/test/performance. When these become available, make sure to run these when you add Photon-y things!
  • Expect big patches to land to stop using Task.jsm in browser/ and toolkit/, and stop using the non standard Promise.defer from promise.jsm
    • If you have WIP patches for these folders, consider landing them soon to avoid bitrot.
  • Fischer and Rex and Fred report that the team has been iterating on the overlay prototype for the onboarding experience
    • The team is in discussions with the Activity Stream team to figure out how the overlay will integrate with the Activity Stream page
    • The team is also sorting out integration with Firefox Account log-in, and Automigration
    • The onboarding overlay experience is currently being developed as a system add-on
  • timdream reports that the team has almost finished scoping out the work for this project, and that this wiki page is a great way to track the team as they work
  • Please file about:preferences bugs! Preferably blocking the right meta bugs.


  • jkt is looking into rewriting containers to use WebExtensions instead of the Addon SDK
  • Our three Outreachy interns for May 30 – August 30 were announced last week:

Project Mortar (PDFium)


Sync / Firefox Accounts

Test Pilot

Here are the raw meeting notes that were used to derive this list.

Want to help us build Firefox? Get started here!

Here’s a tool to find some mentored, good first bugs to hack on.

8 comments on “These Weeks in Firefox: Issue 16”

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  1. Brian wrote on

    Does “e10s-a11y support still targeted for Firefox 55” mean that e10s won’t arrive for windows 64-bit touch until then?


    1. mconley wrote on

      I believe our Platform Integration team was able to decouple touch-screen support from a11y. I _believe_ e10s should be supported on Windows touch in Firefox 54.


  2. klop*cz wrote on

    Thank you for update. Great to read it!


  3. nicolas wrote on

    Hi! Is there a way to try (or even use) Photon currently? I’d love to switch to it as soon as it’s possible and see the work on it as it happens. If not, when should we expect it to land in Nightly? 🙂 Thanks!


    1. Johann Hofmann wrote on

      Hi Nicolas, first visible pieces of Photon have already landed in Nightly and will be enabled by default there (but of course not on any other channel until 57). There’s also the browser.photon.structure.enabled pref which changes the menu structure but is potentially a bit less stable right now.

      These major UI changes are impossible to do without causing regressions, so we highly appreciate you using Nightly and filing bugs whenever you notice something!


  4. Ashhar Hasan wrote on

    Thanks a lot. Really glad to see my name here and looking to forward to contributing more in the coming months.


  5. dude wrote on

    Why is refresh button on the left now and why isn’t it movable via Customize menu?


    1. minimalist wrote on

      Notice the highlighted monstrosity:

      Please remove this enormous waste of precious space on the toolbar that crept in during the last nightly update. The down arrows are absolutely unnecessary, no added value whatsoever, pure graphic bloat.


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