Categories: News

These Weeks in Firefox: Issue 17


Friends of the Firefox team

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

  • Resolved bugs (excluding employees):
    • More than one bug fixed:
      • Dan Banner
      • Kevin Jones
      • Milind L (:milindl)
      • Swapnesh Kumar Sahoo [:swapneshks]
      • tfe
    • New contributors (🌟 = First Patch!)
      • 🌟 jomer14 got rid of some leftover l10n files that Firefox Accounts didn’t need anymore!
      • 🌟 Pauline got rid of PlacesUtils.asyncGetBookmarkIds (which isn’t needed anymore thanks to Bookmarks.jsm), which also reduced our memory footprint!
      • 🌟 Shashwat Jolly cleaned up some of our strings in about:license!

Project Updates

Activity Stream

  • ‘Graduation’ team is getting close to preffing on Activity Stream in Nightly and working on Search Suggestions, about:home, cleaning up tests, and perf telemetry
    • Aiming for more regular / weekly landings from github to mozilla-central
    • Replaced custom React search suggestions from Test Pilot with existing contentSearchUI used for about:home/about:newtab simplifying tests
  • Test Pilot team is finishing up customization (drag’n’drop, add/edit topsite), as well as beginning work on Sections
  • Activity Stream, when enabled on m-c runs in the content process!
  • Removed most of Content Services / Suggested Tiles code from about:newtab resulting in perf improvements and removed / ~8x fewer intermittent test failures

Electrolysis (e10s)

  • The e10s-multi team is still looking over the data being gathered from the Beta population against the release criteria to determine whether or not e10s-multi will ship in Firefox 54, or will have to wait until Firefox 55
  • e10s-a11y support in Firefox 55 has been marked “at risk” due to stability issues. A go/no-go will be happen no later than June 3rd
  • erahm has a blog post about how memory usage with 4 content processes continues to be the sweet spot

Firefox Core Engineering

  • Reminder: Firefox 55 is also installing 64-bit by default on 64-bit OS’s; updates will come later.
  • Resolved race condition in Rust runtime. This may have been bugging some tests (no pun intended).
  • We have preliminary top crashers lists from crash stacks sent via crash pings. Expanding that analysis is pending review of the data & correlation with crash reports.

Form Autofill



  • More rigorous reflow tests have landed for window opening, tab opening and tab closing.
  • Kudos to the Structure / Menus team for making the subview animations smooth as silk! (Notice that Oh no! Reflow! is detecting no synchronous reflows in that video)
  • Task.jsm and Promise.defer() removal big patches landed as pre-announced during the last meeting. This covered the browser/ and toolkit/ folders, more patches coming soon for other folders.


  • The page action menu has started taking shape and now has items to copy/email links, and will soon have a ‘send to device’ submenu;
  • Tomorrow’s nightly will have Firefox Account and cut/copy/paste items in the main hamburger panel;
  • Main work on the permanent overflow panel (as a replacement for the customizable bits of the existing hamburger panel) is done, working on polish and bugfixes;
  • Work will start on the new library button this week;
  • We’ll be working to flip the photon pref by default on Nightly in the next week or two;





  • Search is taking shape on Nightly! It now comes with the right highlight color, tooltips for sub-dialog search results. With the help from QA engineers, we are closing the gap between implementation & spec.
  • UX team asked us to revise re-org. The change will likely postpone re-org shipping by one release (to 56); the good news is the release population will be presented with the new search & re-org at the same time, if that happens.

Project Mortar (PDFium)

  • peterv made some progress of the JSPlugin architecture – the last few pieces of work are reviewing. Hopefully this is the final round of review, and we will land all of them (8 patches!) soon.


  • One-off buttons in the location bar are ready to ride the trains in 55.
  • Search suggestions are now enabled by default. Users who had explicitly opted out of search suggestions in the past, will not see them.
  • Hi-res favicon improvements: the default globe favicon is now hi-res (SVG) everywhere in the UI and some ugly icon rescaling was fixed.

Sync / Firefox Accounts

Test Pilot

  • Containers experiment release 2.3.0 coming this week
    • adds a “site assignment” on-boarding panel to increase site assignments
      A screenshot of a panel explaining how you can choose sites that will always open in a container.
    • Also removes SDK code!
  • Screenshots feature is now aiming for 55
    • We’re hoping WebExtensions start-up will be performant enough by 55
    • Our backup plan: move UI (toolbar button, context menu item) into bootstrap.js code, lazy-load WebExtension on click
  • We’re planning to start a Test Pilot blog (with help from Marketing)
  • Test Pilot and experiments are moving away from the SDK

Looking into replacing Test Pilot addon functionality with a WebExtension API Experiment (learn more)

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.

3 comments on “These Weeks in Firefox: Issue 17”

Post a comment

  1. klop*cz wrote on

    Hello again! Thank you for this information. Nice to read it every time.
    Do you have any idea when FormAutoFill could be usable outside of US country?


  2. uifocused wrote on

    Thanks to whomever finally removed the dropdown arrows on the folders in the bookmark menu. I was already considering a different browser if that ui regression stuck a while longer.


  3. dude wrote on

    Should this be visible on new tabs even when they are set to blank?
    What is this anyway


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