Bug 1724668 - Ensure Pocket panel closes if location changes with locationSpecific CustomizableUI prop. r=Gijs

Differential Revision: https://phabricator.services.mozilla.com/D122278

browser/base/content/browser.js

@@ -2018,16 +2018,6 @@ var gBrowserInit = {
       PanicButtonNotifier.init();
     });
 
-    gBrowser.tabContainer.addEventListener("TabSelect", function() {
-      for (let panel of document.querySelectorAll(
-        "panel[tabspecific='true']"
-      )) {
-        if (panel.state == "open") {
-          panel.hidePopup();
-        }
-      }
-    });
-
     if (BrowserHandler.kiosk) {
       // We don't modify popup windows for kiosk mode
       if (!gURLBar.readOnly) {
@@ -5422,6 +5412,25 @@ var XULBrowserWindow = {
       );
     }
 
+    let closeOpenPanels = selector => {
+      for (let panel of document.querySelectorAll(selector)) {
+        if (panel.state == "open") {
+          panel.hidePopup();
+        }
+      }
+    };
+
+    // If the location is changed due to switching tabs,
+    // ensure we close any open tabspecific panels.
+    if (aIsSimulated) {
+      closeOpenPanels("panel[tabspecific='true']");
+    }
+
+    // Ensure we close any remaining open locationspecific panels
+    if (!isSameDocument) {
+      closeOpenPanels("panel[locationspecific='true']");
+    }
+
     // About pages other than about:reader are not currently supported by
     // screenshots (see Bug 1620992).
     Services.obs.notifyObservers(