1 files changed, 8 insertions, 6 deletions
diff --git a/remote/shared/RecommendedPreferences.sys.mjs b/remote/shared/RecommendedPreferences.sys.mjs
index d0a7739e52..b52057ee2b 100644
--- a/remote/shared/RecommendedPreferences.sys.mjs
+++ b/remote/shared/RecommendedPreferences.sys.mjs
@@ -145,6 +145,9 @@ const COMMON_PREFERENCES = new Map([
   // Do not redirect user when a milstone upgrade of Firefox is detected
   ["browser.startup.homepage_override.mstone", "ignore"],
 
+  // Unload the previously selected tab immediately
+  ["browser.tabs.remote.unloadDelayMs", 0],
+
   // Don't unload tabs when available memory is running low
   ["browser.tabs.unloadOnLowMemory", false],
 
@@ -310,6 +313,9 @@ const COMMON_PREFERENCES = new Map([
   // Privacy and Tracking Protection
   ["privacy.trackingprotection.enabled", false],
 
+  // Used to check if recommended preferences are applied
+  ["remote.prefs.recommended.applied", true],
+
   // Don't do network connections for mitm priming
   ["security.certerrors.mitm.priming.enabled", false],
 
@@ -362,7 +368,7 @@ export const RecommendedPreferences = {
    * @param {Map<string, object>=} preferences
    *     Map of preference name to preference value.
    */
-  applyPreferences(preferences) {
+  applyPreferences(preferences = new Map()) {
     if (!lazy.useRecommendedPrefs) {
       // If remote.prefs.recommended is set to false, do not set any preference
       // here. Needed for our Firefox CI.
@@ -374,11 +380,7 @@ export const RecommendedPreferences = {
     if (!this.isInitialized) {
       // Merge common preferences and optionally provided preferences in a
       // single map. Hereby the extra preferences have higher priority.
-      if (preferences) {
-        preferences = new Map([...COMMON_PREFERENCES, ...preferences]);
-      } else {
-        preferences = COMMON_PREFERENCES;
-      }
+      preferences = new Map([...COMMON_PREFERENCES, ...preferences]);
 
       Services.obs.addObserver(this, "quit-application");
       this.isInitialized = true;