Add experiment to exercise AffiliationService with dummy data, plus add related UMA histograms.

components/password_manager/core/browser/affiliation_backend.h

 // Copyright 2015 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_PASSWORD_MANAGER_CORE_BROWSER_AFFILIATION_BACKEND_H_
 #define COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_AFFILIATION_BACKEND_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 92 matching lines @@
       scoped_ptr<AffiliationFetcherDelegate::Result> result) override;
   void OnFetchFailed() override;
   void OnMalformedResponse() override;
 
   // AffiliationFetchThrottlerDelegate:
   bool OnCanSendNetworkRequest() override;
 
   // Returns the number of in-memory FacetManagers. Used only for testing.
   size_t facet_manager_count_for_testing() { return facet_managers_.size(); }
 
+  // Reports the |requested_facet_uri_count| in a single fetch; and the elapsed
+  // time before the first fetch, and in-between subsequent fetches.
+  void ReportStatistics(size_t requested_facet_uri_count);
+
   // To be called after Initialize() to use |throttler| instead of the default
   // one. Used only for testing.
   void SetThrottlerForTesting(scoped_ptr<AffiliationFetchThrottler> throttler);
 
   // Created in Initialize(), and ensures that all subsequent methods are called
   // on the same thread.
   scoped_ptr<base::ThreadChecker> thread_checker_;
 
   scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   scoped_ptr<base::Clock> clock_;
   scoped_ptr<base::TickClock> tick_clock_;
 
   scoped_ptr<AffiliationDatabase> cache_;
   scoped_ptr<AffiliationFetcher> fetcher_;
   scoped_ptr<AffiliationFetchThrottler> throttler_;
 
+  base::Time construction_time_;
+  base::Time last_request_time_;
+
   // Contains a FacetManager for each facet URI that need ongoing attention. To
   // save memory, managers are discarded as soon as they become redundant.
   base::ScopedPtrHashMap<FacetURI, FacetManager> facet_managers_;
 
   base::WeakPtrFactory<AffiliationBackend> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AffiliationBackend);
 };
 
 }  // namespace password_manager
 
 #endif  // COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_AFFILIATION_BACKEND_H_