Simulate variation seeds using installed version string.

chrome/browser/metrics/variations/variations_service.h

Index: chrome/browser/metrics/variations/variations_service.h
===================================================================
--- chrome/browser/metrics/variations/variations_service.h	(revision 277793)
+++ chrome/browser/metrics/variations/variations_service.h	(working copy)
@@ -10,8 +10,10 @@
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/metrics/field_trial.h"
 #include "base/time/time.h"
+#include "base/version.h"

[Ilya Sherman, 2014/06/17 21:24:59]

nit: Can this be forward-declared?

[Alexei Svitkine (slow), 2014/06/17 22:15:54]

Done.

 #include "chrome/browser/metrics/variations/variations_request_scheduler.h"
 #include "chrome/browser/metrics/variations/variations_seed_store.h"
 #include "chrome/browser/web_resource/resource_request_allowed_notifier.h"
@@ -145,6 +147,10 @@
   // ResourceRequestAllowedNotifier::Observer implementation:
   virtual void OnResourceRequestsAllowed() OVERRIDE;
 
+  // Performs a variations seed simulation with the given |seed| and |version|.

[Ilya Sherman, 2014/06/17 21:24:59]

From just reading the declaration and comment, it's unclear to me why this is a
void method.  What happens to the result of the simulation?

[Alexei Svitkine (slow), 2014/06/17 22:15:54]

Currently, it only logs histograms. In another CL (that's under review) it will
notify observers based on the simulation results. I've expanded the comment to
mention the current behavior.

+  void PerformSimulationWithVersion(scoped_ptr<VariationsSeed> seed,
+                                    const base::Version& version);
+
   // Record the time of the most recent successful fetch.
   void RecordLastFetchTime();
 
@@ -193,6 +199,8 @@
   VariationsRegistrySyncer registry_syncer_;
 #endif
 
+  base::WeakPtrFactory<VariationsService> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(VariationsService);
 };