--- a/browser/base/content/test/tabview/browser_tabview_launch.js
+++ b/browser/base/content/test/tabview/browser_tabview_launch.js
@@ -39,20 +39,18 @@ let tabViewShownCount = 0;
 
 // ----------
 function test() {
   waitForExplicitFinish();
 
   // verify initial state
   ok(!TabView.isVisible(), "Tab View starts hidden");
 
-  // use the Tab View button to launch it for the first time
+  // launch tab view for the first time
   window.addEventListener("tabviewshown", onTabViewLoadedAndShown, false);
-  let button = document.getElementById("tabview-button");
-  ok(!button, "Tab View button not exist by default");
   let tabViewCommand = document.getElementById("Browser:ToggleTabView");
   tabViewCommand.doCommand();
 }
 
 // ----------
 function onTabViewLoadedAndShown() {
   window.removeEventListener("tabviewshown", onTabViewLoadedAndShown, false);
 

--- a/browser/base/content/test/tabview/browser_tabview_rtl.js
+++ b/browser/base/content/test/tabview/browser_tabview_rtl.js
@@ -45,18 +45,16 @@ function test() {
   ok(!TabView.isVisible(), "Tab View starts hidden");
 
   // use the Tab View button to launch it for the first time
   window.addEventListener("tabviewshown", onTabViewLoadedAndShown("ltr"), false);
   toggleTabView();
 }
 
 function toggleTabView() {
-  let button = document.getElementById("tabview-button");
-  ok(!button, "Tab View button not exist by default");
   let tabViewCommand = document.getElementById("Browser:ToggleTabView");
   tabViewCommand.doCommand();
 }
 
 // ----------
 function onTabViewLoadedAndShown(dir) {
   return function() {
     window.removeEventListener("tabviewshown", arguments.callee, false);