Activate the VariationsService for ChromeOS and ensure that it does not ping the server until the E…

chrome/browser/metrics/variations/variations_service.h

 // Copyright (c) 2012 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 CHROME_BROWSER_METRICS_VARIATIONS_VARIATIONS_SERVICE_H_
 #define CHROME_BROWSER_METRICS_VARIATIONS_VARIATIONS_SERVICE_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/field_trial.h"
 #include "base/time.h"
 #include "base/timer.h"
 #include "chrome/browser/metrics/proto/study.pb.h"
 #include "chrome/browser/metrics/proto/trials_seed.pb.h"
+#include "chrome/browser/metrics/variations/resource_request_allowed_notifier.h"
 #include "chrome/common/chrome_version_info.h"
 #include "googleurl/src/gurl.h"
-#include "net/base/network_change_notifier.h"
 #include "net/url_request/url_fetcher_delegate.h"
 
 class PrefService;
 
+namespace chromeos {
+class WizardController;
+}
+
 namespace chrome_variations {
 
 // Used to setup field trials based on stored variations seed data, and fetch
 // new seed data from the variations server.
 class VariationsService
     : public net::URLFetcherDelegate,
-      public net::NetworkChangeNotifier::ConnectionTypeObserver{
+      public ResourceRequestAllowedNotifier::Observer {
  public:
   VariationsService();
   virtual ~VariationsService();
 
   // Creates field trials based on Variations Seed loaded from local prefs. If
   // there is a problem loading the seed data, all trials specified by the seed
   // may not be created.
   bool CreateTrialsFromSeed(PrefService* local_prefs);
 
   // Calls FetchVariationsSeed once and repeats this periodically. See
   // implementation for details on the period. Must be called after
   // |CreateTrialsFromSeed|.
   void StartRepeatedVariationsSeedFetch();
 
+  // Checks if prerequisites for fetching the Variations seed are met, and if
+  // so, performs the actual fetch using |DoActualFetch|.
+  void FetchVariationsSeed();
+
+  // Register Variations related prefs in Local State.
+  static void RegisterPrefs(PrefService* prefs);
+
+ protected:
   // Starts the fetching process once, where |OnURLFetchComplete| is called with
   // the response. If the network is down at the time, sets a flag to retry when
   // the network is back online. This is virtual so it can be overriden for
   // testing.
-  virtual void FetchVariationsSeed();
+  virtual void DoActualFetch();

[Alexei Svitkine (slow), 2012/09/19 19:44:28]

Why the name change?

[SteveT, 2012/09/20 19:40:18]

I separated all the URLFetchRequest stuff into this method (notice that
FetchVariationsSeed still exists above) so I can mock this method to see if it
gets called based on notifications from the RRANotifier.

Let me know if there is a preferable pattern.

 
-  // Exposed for testing.
-  void SetWasOfflineDuringLastRequestAttemptForTesting(bool offline);
+  // Allows tests to replace |resource_request_allowed_notifier_| with a mock.
+  void SetResourceRequestAllowedNotifierForTesting(
+      ResourceRequestAllowedNotifier* notifier);
 
-  // Register Variations related prefs in Local State.
-  static void RegisterPrefs(PrefService* prefs);
+  // Tracks whether |CreateTrialsFromSeed| has been called, to ensure that
+  // it gets called prior to |StartRepeatedVariationsSeedFetch|.
+  // This field is protected so test classes can modify it.
+  bool create_trials_from_seed_called_;

[Alexei Svitkine (slow), 2012/09/19 19:44:28]

I suggest instead making *ForTesting() getters and setters and keeping this
private.

[SteveT, 2012/09/20 19:40:18]

Done.

 
  private:
   FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyChannel);
   FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyLocale);
   FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyPlatform);
   FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyVersion);
   FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyVersionWildcards);
   FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, CheckStudyStartDate);
   FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, DoNotFetchIfOffline);
   FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, DoNotFetchIfOnlineToOnline);
   FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, FetchOnReconnect);
   FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, IsStudyExpired);
-  FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, LoadSeed);
-  FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, StoreSeed);
+  FRIEND_TEST_ALL_PREFIXES(VariationsServiceCreatedTest, LoadSeed);
+  FRIEND_TEST_ALL_PREFIXES(VariationsServiceCreatedTest, StoreSeed);
   FRIEND_TEST_ALL_PREFIXES(VariationsServiceTest, ValidateStudy);
 
   // net::URLFetcherDelegate implementation:
   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
 
-  // net::NetworkChangeNotifier::ConnectionTypeObserver implementation.
-  virtual void OnConnectionTypeChanged(
-      net::NetworkChangeNotifier::ConnectionType type) OVERRIDE;
+  // ResourceRequestAllowedNotifier::Observer implementation:
+  virtual void OnResourceRequestsAllowed() OVERRIDE;
 
   // Store the given seed data to the given local prefs. Note that |seed_data|
   // is assumed to be the raw serialized protobuf data stored in a string. It
   // will be Base64Encoded for storage. If the string is invalid or the encoding
   // fails, the |local_prefs| is left as is and the function returns false.
   bool StoreSeedData(const std::string& seed_data,
                      const base::Time& seed_date,
                      PrefService* local_prefs);
 
   // Returns whether |study| should be disabled according to its restriction
@@ skipping 46 matching lines @@
   // Contains the current seed request. Will only have a value while a request
   // is pending, and will be reset by |OnURLFetchComplete|.
   scoped_ptr<net::URLFetcher> pending_seed_request_;
 
   // The URL to use for querying the Variations server.
   GURL variations_server_url_;
 
   // Cached serial number from the most recently fetched Variations seed.
   std::string variations_serial_number_;
 
-  // Tracks whether |CreateTrialsFromSeed| has been called, to ensure that
-  // it gets called prior to |StartRepeatedVariationsSeedFetch|.
-  bool create_trials_from_seed_called_;
-
-  // Tracks whether or not the last seed request attempt failed due to being
-  // offline.
-  bool was_offline_during_last_request_attempt_;
-
   // The timer used to repeatedly ping the server. Keep this as an instance
   // member so if VariationsService goes out of scope, the timer is
   // automatically canceled.
   base::RepeatingTimer<VariationsService> timer_;
+
+  // Helper class used to tell this service if it's allowed to make network
+  // resource requests.
+  scoped_ptr<ResourceRequestAllowedNotifier> resource_request_allowed_notifier_;
 };
 
 }  // namespace chrome_variations
 
 #endif  // CHROME_BROWSER_METRICS_VARIATIONS_VARIATIONS_SERVICE_H_