Remove NOTIFICATION_TAB_ADDED from ui_test_utils.cc

Bug: 268984
Change-Id: I36440e22f2d15a63aa5aba46b0f062eafdb11e33
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1715530
Auto-Submit: Evan Stade <estade@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#686625}

chrome/test/base/ui_test_utils.cc

@@ -288,16 +288,14 @@ NavigateToURLWithDispositionBlockUntilNavigationsComplete(
   for (auto* browser : *BrowserList::GetInstance())
     initial_browsers.insert(browser);
 
-  content::WindowedNotificationObserver tab_added_observer(
-      chrome::NOTIFICATION_TAB_ADDED,
-      content::NotificationService::AllSources());
+  AllBrowserTabAddedWaiter tab_added_waiter;
 
   browser->OpenURL(OpenURLParams(
       url, Referrer(), disposition, ui::PAGE_TRANSITION_TYPED, false));
   if (browser_test_flags & BROWSER_TEST_WAIT_FOR_BROWSER)
     browser = WaitForBrowserNotInSet(initial_browsers);
   if (browser_test_flags & BROWSER_TEST_WAIT_FOR_TAB)
-    tab_added_observer.Wait();
+    tab_added_waiter.Wait();
   if (!(browser_test_flags & BROWSER_TEST_WAIT_FOR_NAVIGATION)) {
     // Some other flag caused the wait prior to this.
     return nullptr;
@@ -654,6 +652,9 @@ void AllBrowserTabAddedWaiter::OnTabStripModelChanged(
     TabStripModel* tab_strip_model,
     const TabStripModelChange& change,
     const TabStripSelectionChange& selection) {
+  if (web_contents_)
+    return;
+
   if (change.type() != TabStripModelChange::kInserted)
     return;