Added retry policy

chrome/browser/chromeos/login/enrollment/enrollment_screen.h

Index: chrome/browser/chromeos/login/enrollment/enrollment_screen.h
diff --git a/chrome/browser/chromeos/login/enrollment/enrollment_screen.h b/chrome/browser/chromeos/login/enrollment/enrollment_screen.h
index 9bd361d02b6e9e8e6dcc67087a95b164bba53c67..97f3ac0c53b0d13ca1d212774f77176c5f14168f 100644
--- a/chrome/browser/chromeos/login/enrollment/enrollment_screen.h
+++ b/chrome/browser/chromeos/login/enrollment/enrollment_screen.h
@@ -13,12 +13,14 @@
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "base/timer/timer.h"
 #include "chrome/browser/chromeos/login/enrollment/enrollment_screen_actor.h"
 #include "chrome/browser/chromeos/login/enrollment/enterprise_enrollment_helper.h"
 #include "chrome/browser/chromeos/login/screens/base_screen.h"
 #include "chrome/browser/chromeos/policy/enrollment_config.h"
 #include "components/policy/core/common/cloud/cloud_policy_constants.h"
 #include "components/policy/core/common/cloud/enterprise_metrics.h"
+#include "net/base/backoff_entry.h"
 
 namespace base {
 class ElapsedTimer;
@@ -146,6 +148,14 @@ class EnrollmentScreen
   // Advance to the next authentication mechanism if possible.
   bool AdvanceToNextAuth();
 
+  // Similar to OnRetry(), but responds to a timer instead of the user
+  // pressing the Retry button.
+  void AutomaticRetry();
+
+  // Processes a request to retry enrollment.
+  // Called by OnRetry() and AutomaticRetry().
+  void ProcessRetry();
+
   pairing_chromeos::ControllerPairingController* shark_controller_ = nullptr;
 
   EnrollmentScreenActor* actor_;
@@ -157,6 +167,10 @@ class EnrollmentScreen
   std::string enrolling_user_domain_;
   std::string auth_code_;
   std::unique_ptr<base::ElapsedTimer> elapsed_timer_;
+  base::OneShotTimer retry_timer_;

[The one and only Dr. Crash, 2016/12/06 22:24:33]

Instead of using a timer, you can simply post delayed tasks to your message
loop. See this CL as an example: https://codereview.chromium.org/2529743002/

+  net::BackoffEntry::Policy retry_policy_;
+  net::BackoffEntry retry_backoff_;
+  int num_retries_;
   std::unique_ptr<EnterpriseEnrollmentHelper> enrollment_helper_;
   base::WeakPtrFactory<EnrollmentScreen> weak_ptr_factory_;