Categories: Uncategorized

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.

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