Bug 1022202 - Fix uncaught nsIScrollBoxObject.ensureElementIsVisible promise rejections in the netmonitor tests, r=dcamp

browser/devtools/netmonitor/netmonitor-controller.js

@@ -223,6 +223,14 @@ let NetMonitorController = {
     this.webConsoleClient = null;
   },
 
+  /**
+   * Checks whether the netmonitor connection is active.
+   * @return boolean
+   */
+  isConnected: function() {
+    return !!this.client;
+  },
+
   /**
    * Sets up a monitoring session.
    *

browser/devtools/netmonitor/netmonitor-view.js

@@ -1980,6 +1980,8 @@ NetworkDetailsView.prototype = {
    */
   destroy: function() {
     dumpn("Destroying the NetworkDetailsView");
+
+    $("tabpanels", this.widget).removeEventListener("select", this._onTabSelect);
   },
 
   /**
@@ -2068,7 +2070,10 @@ NetworkDetailsView.prototype = {
       }
       populated[tab] = true;
       window.emit(EVENTS.TAB_UPDATED);
-      NetMonitorView.RequestsMenu.ensureSelectedItemIsVisible();
+
+      if (NetMonitorController.isConnected()) {
+        NetMonitorView.RequestsMenu.ensureSelectedItemIsVisible();
+      }
     });
   },