Backed out changeset 438624f92fbc

browser/base/content/tabbrowser.xml

@@ -2078,13 +2078,6 @@
               let getter;
               let setter;
               switch (name) {
-                case "permitUnload":
-                  getter = () => {
-                    return function() {
-                      return { permitUnload: true, timedOut: false };
-                    };
-                  };
-                  break;
                 default:
                   getter = () => {
                     this._insertBrowser(aTab);
@@ -5295,20 +5288,15 @@
                                                        browser.getAttribute("usercontextid") || 0);
               delete browser.registeredOpenURI;
             }
-
             let filter = this._tabFilters.get(tab);
-            if (filter) {
-              browser.webProgress.removeProgressListener(filter);
+            let listener = this._tabListeners.get(tab);
 
-              let listener = this._tabListeners.get(tab);
-              if (listener) {
-                filter.removeProgressListener(listener);
-                listener.destroy();
-              }
+            browser.webProgress.removeProgressListener(filter);
+            filter.removeProgressListener(listener);
+            listener.destroy();
 
-              this._tabFilters.delete(tab);
-              this._tabListeners.delete(tab);
-            }
+            this._tabFilters.delete(tab);
+            this._tabListeners.delete(tab);
           }
           const nsIEventListenerService =
             Components.interfaces.nsIEventListenerService;

browser/components/sessionstore/TabStateFlusher.jsm

@@ -84,11 +84,6 @@ var TabStateFlusherInternal = {
    * all the latest data.
    */
   flush(browser) {
-    let tabbrowser = browser.ownerGlobal.gBrowser;
-    if (!tabbrowser.getTabForBrowser(browser).linkedPanel) {
-      return;
-    }
-
     let id = ++this._lastRequestID;
     let mm = browser.messageManager;
     mm.sendAsyncMessage("SessionStore:flush", {id});