Disable BrowserCloseManagerBrowserTest.AddBeforeUnloadDuringClosing on Mac.

chrome/browser/lifetime/browser_close_manager_browsertest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/lifetime/browser_close_manager.h"
 
 #include <utility>
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 723 matching lines @@
   ASSERT_NO_FATAL_FAILURE(AcceptClose());
   ASSERT_NO_FATAL_FAILURE(AcceptClose());
   ASSERT_NO_FATAL_FAILURE(AcceptClose());
   ASSERT_NO_FATAL_FAILURE(AcceptClose());
 
   close_observer.Wait();
   EXPECT_TRUE(browser_shutdown::IsTryingToQuit());
   EXPECT_TRUE(BrowserList::GetInstance()->empty());
 }
 
+// TODO(crbug/713201):
+// BrowserCloseManagerBrowserTest.AddBeforeUnloadDuringClosing flaky on Mac.
+#if defined(OS_MACOSX)
+#define MAYBE_AddBeforeUnloadDuringClosing DISABLED_AddBeforeUnloadDuringClosing
+#else
+#define MAYBE_AddBeforeUnloadDuringClosing AddBeforeUnloadDuringClosing
+#endif
+
 IN_PROC_BROWSER_TEST_P(BrowserCloseManagerBrowserTest,
-                       AddBeforeUnloadDuringClosing) {
+                       MAYBE_AddBeforeUnloadDuringClosing) {
   // TODO(crbug.com/250305): Currently FastUnloadController is broken.
   // And it is difficult to fix this issue without fixing that one.
   if (GetParam())
     return;
 
   ASSERT_TRUE(embedded_test_server()->Start());
   ASSERT_NO_FATAL_FAILURE(ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL("/title1.html")));
 
   // Open second window.
@@ skipping 522 matching lines @@
 
   chrome::CloseAllBrowsers();
   EXPECT_FALSE(browser_shutdown::IsTryingToQuit());
   EXPECT_TRUE(BrowserList::GetInstance()->empty());
   EXPECT_TRUE(IsBackgroundModeSuspended());
 }
 
 INSTANTIATE_TEST_CASE_P(BrowserCloseManagerWithBackgroundModeBrowserTest,
                         BrowserCloseManagerWithBackgroundModeBrowserTest,
                         testing::Bool());