arc: Provide UMA for OptIn flow.

chrome/browser/chromeos/arc/arc_session_manager.h

Index: chrome/browser/chromeos/arc/arc_session_manager.h
diff --git a/chrome/browser/chromeos/arc/arc_session_manager.h b/chrome/browser/chromeos/arc/arc_session_manager.h
index cfd26dbd189b0b9e2f651959e8d4a5f10b559f5c..f1aeeff8c0e22e546b958b31765bc6c38ee485d7 100644
--- a/chrome/browser/chromeos/arc/arc_session_manager.h
+++ b/chrome/browser/chromeos/arc/arc_session_manager.h
@@ -302,6 +302,13 @@ class ArcSessionManager : public ArcSessionRunner::Observer,
   // is fixed.
   void MaybeReenableArc();
 
+  // Starts tracking of OptIn flow. Tracked flows are reported to UMA.
+  void StartOptInFlowTracking();

[Luis Héctor Chávez, 2017/03/30 15:49:25]

Can we abstract this logic to stop giving too much responsibility to this class?

class ScopedOptInFlowTracker {
 public:
  ScopedOptInFlowTracker() { /* ... */ };
  ~ScopedOptInFlowTracker() { /* ... */ }
  TrackRetry() { retried_ = true; }
  TrackSuccess() { success_ = true; }
 private:
  bool retried_ = false;
  bool success_ = false;
}

then replace calls to StartOptInFlowTracking with scoped_opt_in_tracker_ =
base::MakeUnique<...>();

and StopOptInFlowTracking with scoped_opt_in_tracker_.reset();

[khmel, 2017/03/30 17:01:43]

That nice, thanks

+
+  // Stop tracking of OptIn flow. |succeeded| indicates that flow finished
+  // successfully.
+  void StopOptInFlowTracking(bool succeeded);
+
   std::unique_ptr<ArcSessionRunner> arc_session_runner_;
 
   // Unowned pointer. Keeps current profile.
@@ -317,6 +324,8 @@ class ArcSessionManager : public ArcSessionRunner::Observer,
   std::unique_ptr<ArcAppLauncher> playstore_launcher_;
   bool reenable_arc_ = false;
   bool provisioning_reported_ = false;
+  bool optin_flow_tracked_ = false;
+  bool optin_flow_error_detected_ = false;
   base::OneShotTimer arc_sign_in_timer_;
 
   std::unique_ptr<ArcSupportHost> support_host_;