Firefox 44 附加组件兼容性

Firefox 44 will be released on January 26th. Here’s the list of changes that went into this version
 that can affect add-on compatibility. There is more information
available in Firefox 44 for Developers, so you should also give it a look.

General

• Move DevTools code to /devtools top-level directory. This includes changing a number of paths that could affect themes and extensions. Notably, JS Modules related to the dev tools now all live under resource://devtools/.
• Opening the “View” > “Page Style” menu causes unsafe CPOW usage warnings. This change removes the global getAllStyleSheets function and introduces the similar (but not identical) getBrowserStyleSheets.
• Stop doing random work in sessionstore for localStorage changes. This splits the MozStorageChanged event into MozSessionStorageChanged and MozLocalStorageChanged.
• Stop supporting installation of Sherlock plugins from the web. Search provider add-ons should be implemented using OpenSearch.
• Allow about: pages to load remote content. This bug deprecates NewTabUrl.jsm, read this comment for details.

JavaScript

• Breaking changes in let and const. Firefox 44 finally brings the let and const implementation up to standard, which also means some
  backward-incompatible changes had to be implemented. Read the linked
  blog post for the details.
• Remove __noSuchMethod__. ES6 proxies are a suitable alternative for many use cases.

Theme

• Simplify gIdentityHandler. This affects add-ons that depended on the level attribute of #urlbar, which is no longer used. This comment explains what you can do instead.
• Impose size restriction on extension icons. This prevents too large toolbar icons from deforming the toolbar.
• alert() steals focus from other tab. This introduces various changes to the tabbrowser binding which could break themes.
• Remove outset border from notification bars.

Signing

• Firefox 43 is currently enforcing add-on signing,
   with a preference to override it. Firefox 44 will remove the preference
   entirely, which means your add-on will need to be signed in order to
  run in release versions of Firefox. You can read about your options here.

http://blog.mozilla.org/addons/2015/12/29/compatibility-for-firefox-44/