Add testing configs for ParseHTMLOnMainThread experiment

chrome/browser/extensions/extension_resource_request_policy_apitest.cc

Index: chrome/browser/extensions/extension_resource_request_policy_apitest.cc
diff --git a/chrome/browser/extensions/extension_resource_request_policy_apitest.cc b/chrome/browser/extensions/extension_resource_request_policy_apitest.cc
index db8a6065555358bd2dde5327d29a6f03180bf70c..c3b2a14a90fb0ed57974db50df775ec24b80ed7b 100644
--- a/chrome/browser/extensions/extension_resource_request_policy_apitest.cc
+++ b/chrome/browser/extensions/extension_resource_request_policy_apitest.cc
@@ -12,6 +12,7 @@
 #include "chrome/test/base/test_switches.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/notification_service.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/test/browser_test_utils.h"
@@ -261,27 +262,25 @@ IN_PROC_BROWSER_TEST_F(ExtensionResourceRequestPolicyTest,
       &result));
   EXPECT_EQ("about:blank", result);
 
+  // Redirects can sometimes occur before the load event, so use a
+  // UrlLoadObserver instead of blocking waiting for two load events.
+  ui_test_utils::UrlLoadObserver accessible_observer(
+      GURL("chrome-extension://ggmldgjhdenlnjjjmehkomheglpmijnf/test.png"),
+      content::NotificationService::AllSources());
   GURL accessible_client_redirect_resource(embedded_test_server()->GetURL(
       "/extensions/api_test/extension_resource_request_policy/"
       "web_accessible/accessible_redirect_resource.html"));
-  ui_test_utils::NavigateToURLBlockUntilNavigationsComplete(browser(),
-      accessible_client_redirect_resource, 2);
-  ASSERT_TRUE(content::ExecuteScriptAndExtractString(
-      browser()->tab_strip_model()->GetActiveWebContents(),
-      "window.domAutomationController.send(document.URL)",
-      &result));
-  EXPECT_NE("about:blank", result);
+  ui_test_utils::NavigateToURL(browser(), accessible_client_redirect_resource);
+  accessible_observer.Wait();
 
+  ui_test_utils::UrlLoadObserver nonaccessible_observer(
+      GURL("about:blank"), content::NotificationService::AllSources());
   GURL nonaccessible_client_redirect_resource(embedded_test_server()->GetURL(
       "/extensions/api_test/extension_resource_request_policy/"
       "web_accessible/nonaccessible_redirect_resource.html"));
-  ui_test_utils::NavigateToURLBlockUntilNavigationsComplete(browser(),
-      nonaccessible_client_redirect_resource, 2);
-  ASSERT_TRUE(content::ExecuteScriptAndExtractString(
-      browser()->tab_strip_model()->GetActiveWebContents(),
-      "window.domAutomationController.send(document.URL)",
-      &result));
-  EXPECT_EQ("about:blank", result);
+  ui_test_utils::NavigateToURL(browser(),
+                               nonaccessible_client_redirect_resource);
+  nonaccessible_observer.Wait();
 }
 
 IN_PROC_BROWSER_TEST_F(ExtensionResourceRequestPolicyTest,