AfterStartupTask: Use ForTesting() method rather than friends.

chrome/browser/after_startup_task_utils.cc

Index: chrome/browser/after_startup_task_utils.cc
diff --git a/chrome/browser/after_startup_task_utils.cc b/chrome/browser/after_startup_task_utils.cc
index a55104695522c7d8156b8299a4d11276c4ff8658..85fe8492d2c6b4386c8ab65861e710e7029f723e 100644
--- a/chrome/browser/after_startup_task_utils.cc
+++ b/chrome/browser/after_startup_task_utils.cc
@@ -207,6 +207,10 @@ void AfterStartupTaskUtils::PostTask(
   QueueTask(queued_task.Pass());
 }
 
+void AfterStartupTaskUtils::SetBrowserStartupIsCompleteForTesting() {
+  ::SetBrowserStartupIsComplete();
+}
+
 void AfterStartupTaskUtils::SetBrowserStartupIsComplete() {
   ::SetBrowserStartupIsComplete();
 }