[Doodle] Record UMA for DoodleConfig download outcome and time

components/doodle/doodle_service.h

 // Copyright 2017 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.
 
 #ifndef COMPONENTS_DOODLE_DOODLE_SERVICE_H_
 #define COMPONENTS_DOODLE_DOODLE_SERVICE_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "base/optional.h"
 #include "base/time/clock.h"
+#include "base/time/tick_clock.h"
 #include "base/timer/timer.h"
 #include "components/doodle/doodle_fetcher.h"
 #include "components/doodle/doodle_types.h"
 #include "components/keyed_service/core/keyed_service.h"
 
 class PrefRegistrySimple;
 class PrefService;
 
 namespace base {
 class TimeDelta;
 }
 
 namespace doodle {
 
 class DoodleService : public KeyedService {
  public:
   class Observer {
    public:
     virtual void OnDoodleConfigUpdated(const base::Optional<DoodleConfig>&) = 0;
   };
 
   static void RegisterProfilePrefs(PrefRegistrySimple* pref_registry);
 
   // All parameters must be non-null.
   DoodleService(PrefService* pref_service,
                 std::unique_ptr<DoodleFetcher> fetcher,
                 std::unique_ptr<base::OneShotTimer> expiry_timer,
-                std::unique_ptr<base::Clock> clock);
+                std::unique_ptr<base::Clock> clock,
+                std::unique_ptr<base::TickClock> tick_clock);
   ~DoodleService() override;
 
   // KeyedService implementation.
   void Shutdown() override;
 
   // Returns the current (cached) config, if any.
   const base::Optional<DoodleConfig>& config() const { return cached_config_; }
 
   // Adds a new observer to the service. It'll only be called when the config
   // changes; to get the current (cached) config, call |config()|.
   void AddObserver(Observer* observer);
 
   // Prevents |observer| from receiving future updates. This is safe to call
   // even when the observer is being notified of an update.
   void RemoveObserver(Observer* observer);
 
   // Requests an asynchronous refresh of the DoodleConfig from the network.
   // After the update completes, the observers will be notified only if the
   // config changed.
   void Refresh();
 
  private:
+  // Note: Keep in sync with the corresponding enum in histograms.xml. Never
+  // remove values, and only insert new values at the end.
+  enum DownloadOutcome {
+    OUTCOME_NEW_DOODLE = 0,
+    OUTCOME_REVALIDATED_DOODLE = 1,
+    OUTCOME_CHANGED_DOODLE = 2,
+    OUTCOME_NO_DOODLE = 3,
+    OUTCOME_EXPIRED = 4,
+    OUTCOME_DOWNLOAD_ERROR = 5,
+    OUTCOME_PARSING_ERROR = 6,
+    // Insert new values here!
+    OUTCOME_COUNT = 7
+  };
+
+  static bool DownloadOutcomeIsSuccess(DownloadOutcome outcome);
+  static void RecordDownloadMetrics(DownloadOutcome outcome,
+                                    base::TimeDelta download_time);
+
+  static DownloadOutcome DetermineDownloadOutcome(
+      const base::Optional<DoodleConfig>& old_config,
+      const base::Optional<DoodleConfig>& new_config,
+      DoodleState state,
+      bool expired);
+
   // Callback for the fetcher.
-  void DoodleFetched(DoodleState state,
+  void DoodleFetched(base::TimeTicks start_time,

[fhorschig, 2017/03/22 09:47:10]

nit: const base::TimeTicks& ?
(I guess like for TimeDelta, it's mostly an int)

[Marc Treib, 2017/03/22 10:47:22]

Yup, all the Time types are just an int64, so they're fine to pass by value.

+                     DoodleState state,
                      base::TimeDelta time_to_live,
                      const base::Optional<DoodleConfig>& doodle_config);
 
+  DownloadOutcome HandleNewConfig(
+      DoodleState state,
+      base::TimeDelta time_to_live,
+      const base::Optional<DoodleConfig>& doodle_config);
+
   void UpdateCachedConfig(base::TimeDelta time_to_live,
-                          const base::Optional<DoodleConfig>& doodle_config);
+                          const base::Optional<DoodleConfig>& new_config);
 
   // Callback for the expiry timer.
   void DoodleExpired();
 
   PrefService* pref_service_;
 
   // The fetcher for getting fresh DoodleConfigs from the network.
   std::unique_ptr<DoodleFetcher> fetcher_;
 
   std::unique_ptr<base::OneShotTimer> expiry_timer_;
   std::unique_ptr<base::Clock> clock_;
+  std::unique_ptr<base::TickClock> tick_clock_;
 
   // The result of the last network fetch.
   base::Optional<DoodleConfig> cached_config_;
 
   // The list of observers to be notified when the DoodleConfig changes.
   base::ObserverList<Observer> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(DoodleService);
 };
 
 }  // namespace doodle
 
 #endif  // COMPONENTS_DOODLE_DOODLE_SERVICE_H_