Categories: Uncategorized

These Weeks in Firefox: Issue 102


Friends of the Firefox team
Fixed more than one bug

  • Itiel

Project Updates

Add-ons / Web Extensions

Addon Manager & about:addons

  • Fixed a bug related to the addon descriptions not being localized as expected when switching the browser to a different locale – Bug 1712024
  • Introduced a new “extensions.logging.productaddons.level” about:config pref to control log level related to GMP updates independently from the general AddonManager/XPIProvider logging level – Bug 1733670  

WebExtensions Framework

WebExtension APIs

  • Starting from Firefox 94, a new partitionKey property is being introduced in the cookies API, this new property is meant to help extensions to better handle cookies partitioned by the dFPI feature

Downloads Panel

  • Many tests being addressed and fixed with improvements pref enabled (ticket)
  • [kpatenio] New context menu item being worked on for new pref (ticket)


  • The Fission experiment on Release has concluded, and the data science team is now analyzing the data. So far, nothing has jumped out to us showing stability or performance issues.
  • Barring any serious issues in the data analysis, the plan is to slowly rollout Fission to more release channel users in subsequent releases.


Password Manager 


  • dthayer landed a fix that improves scaling of iframes with Fission enabled
  • mconley helped harry find a solution for a white flash that can occur when a theme is applied to about:home during the first boot
  • Special shout-out to zombie from the WebExtensions team for helping to reduce Base Content JS memory usage by 3-4% on all desktop platforms!
  • We’re starting to get numbers back on how the Fluent migrations have been impacting startup:
    • There appears to be evidence that the localization cycle for the first window is ~32% faster for the 95th percentile of users on Nightly, and ~12% faster for the 75th percentile.
    • Subsequent new windows see localization cycle improvements of ~12% for the 95th percentile
    • TL;DR: Removing DTDs from the main windows has improved startup time and new window opening for some of the slowest machines in our user pool.

Performance Tools

  • Isolated web content processes now display eTLD+1 of their origin in the Firefox Profiler timeline when Fission is enabled.
Before Fission was enabled, web content processes did not display their origin in the Firefox Profiler..


After Fission is enabled, users can now see the origin of web content processes in the Firefox Profiler.


  • Gecko profiler Rust marker API has landed. It’s possible to add a profiler marker from the Rust to annotate a part of the code now. See the gecko-profiler crate for more information. Documentation is also coming soon.

Search and Navigation

  • Daisuke has replaced the DDG icon with one having better quality. Bug 1731538 
  • Thanks to Antonin Loubiere for contributing a patch to make ESC actually undo changes in the separate search bar, instead of doing nothing, more similarly to how the address bar behaves. Bug 350079 


  • Thanks again to module owner Emma whose last day was Friday. Sam Foster will take over as module owner. 
  • niklas working on bug 1714234 that fixes screenshot test issues when copying image to clipboard.

No comments yet

Post a comment

Leave a Reply

Your email address will not be published. Required fields are marked *