gh-13015: Fixed tablist scroll beibg occasionally stuck (gh-13017)

src/toolkit/content/widgets/arrowscrollbox-js.patch

@@ -1,5 +1,5 @@
 diff --git a/toolkit/content/widgets/arrowscrollbox.js b/toolkit/content/widgets/arrowscrollbox.js
-index b80d1049bb6ae305f2ac9c4c35fe975fd508031c..be2cbdb20cb2064459b6f7bef56fd0470c3b7f40 100644
+index b80d1049bb6ae305f2ac9c4c35fe975fd508031c..574149bffa49329e927c8db9db0c080eb6b87f5f 100644
 --- a/toolkit/content/widgets/arrowscrollbox.js
 +++ b/toolkit/content/widgets/arrowscrollbox.js
 @@ -98,6 +98,7 @@
@@ -10,7 +10,19 @@ index b80d1049bb6ae305f2ac9c4c35fe975fd508031c..be2cbdb20cb2064459b6f7bef56fd047
          let contentSize =
            slot.getBoundingClientRect()[this.#verticalMode ? "height" : "width"];
          // NOTE(emilio): This should be contentSize > scrollClientSize, but due
-@@ -642,7 +643,7 @@
+@@ -125,6 +126,11 @@
+       overflowObserver.observe(this.scrollbox);
+     }
+ 
++    connectedMoveCallback() {
++      // See gh-13015, define connectedMoveCallback to prevent connectedCallback
++      // from being called when using moveBefore.
++    }
++
+     connectedCallback() {
+       this.removeAttribute("overflowing");
+ 
+@@ -642,7 +648,7 @@
  
      on_wheel(event) {
        // Don't consume the event if we can't scroll.