Bug 1438055 - Switch Fluent Localization class to use weak observers. r=mossop

MozReview-Commit-ID: 4R8OyziLRUo

--HG--
extra : rebase_source : 8a26c97c30e46af0a5f77060066046cd91ccb64c

intl/l10n/Localization.jsm

@@ -21,6 +21,7 @@
 /* eslint no-console: ["error", { allow: ["warn", "error"] }] */
 /* global console */
 
+const { XPCOMUtils } = ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm", {});
 const { L10nRegistry } = ChromeUtils.import("resource://gre/modules/L10nRegistry.jsm", {});
 const LocaleService = Cc["@mozilla.org/intl/localeservice;1"].getService(Ci.mozILocaleService);
 const ObserverService = Cc["@mozilla.org/observer-service;1"].getService(Ci.nsIObserverService);
@@ -254,11 +255,11 @@ class Localization {
   }
 
   /**
-   * Register observers on events that will trigger cache invalidation
+   * Register weak observers on events that will trigger cache invalidation
    */
   registerObservers() {
-    ObserverService.addObserver(this, 'l10n:available-locales-changed', false);
+    ObserverService.addObserver(this, 'l10n:available-locales-changed', true);
-    ObserverService.addObserver(this, 'intl:requested-locales-changed', false);
+    ObserverService.addObserver(this, 'intl:requested-locales-changed', true);
   }
 
   /**
@@ -296,6 +297,10 @@ class Localization {
   }
 }
 
+Localization.prototype.QueryInterface = XPCOMUtils.generateQI([
+  Ci.nsISupportsWeakReference
+]);
+
 /**
  * Format the value of a message into a string.
  *