Marked WindowLocationTest.WindowLocationReload as flaky on device.

ios/web/navigation/window_location_inttest.mm

 // Copyright 2016 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.
 
 #import "base/mac/bind_objc_block.h"
 #include "base/mac/foundation_util.h"
 #include "base/memory/ptr_util.h"
 #import "base/strings/sys_string_conversions.h"
 #include "base/test/ios/wait_util.h"
 #import "ios/web/public/navigation_item.h"
@@ skipping 184 matching lines @@
   ASSERT_TRUE(web::test::TapWebViewElementWithId(web_state(),
                                                  kWindowLocationReplaceID));
 
   // Wait for the no-op text to appear.
   base::test::ios::WaitUntilCondition(^bool {
     return IsNoOpTextVisible();
   });
 }
 
 // Tests that calling window.location.reload() causes an onload event to occur.
-TEST_F(WindowLocationTest, WindowLocationReload) {
+#if TARGET_IPHONE_SIMULATOR
+#define MAYBE_WindowLocationReload WindowLocationReload
+#else
+#define MAYBE_WindowLocationReload FLAKY_WindowLocationReload
+#endif
+// TODO(crbug.com/721465): Enable this test on device.
+TEST_F(WindowLocationTest, MAYBE_WindowLocationReload) {
   // Tap the window.location.reload() button.
   ExecuteBlockAndWaitForLoad(window_location_url(), ^{
     ASSERT_TRUE(web::test::TapWebViewElementWithId(web_state(),
                                                    kWindowLocationReloadID));
   });
 
   // Verify that |kOnLoadText| is displayed and that no additional
   // NavigationItems are added.
   EXPECT_TRUE(IsOnLoadTextVisible());
   EXPECT_EQ(1, navigation_manager()->GetItemCount());
@@ skipping 18 matching lines @@
   SetWindowLocationUrl(sample_url);
   ExecuteBlockAndWaitForLoad(sample_url, ^{
     ASSERT_TRUE(web::test::TapWebViewElementWithId(
         web_state(), kWindowLocationSetToDOMStringID));
   });
 
   // Verify that |sample_url| was loaded and that |about_blank_item| was pruned.
   EXPECT_EQ(sample_url, navigation_manager()->GetLastCommittedItem()->GetURL());
   EXPECT_EQ(NSNotFound, GetIndexOfNavigationItem(about_blank_item));
 }