Add plumbing for accessing latest country in variations service in Java

components/variations/service/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 COMPONENTS_VARIATIONS_SERVICE_VARIATIONS_SERVICE_H_
 #define COMPONENTS_VARIATIONS_SERVICE_VARIATIONS_SERVICE_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 110 matching lines @@
   // Returns the permanent country code stored for this client. Country code is
   // in the format of lowercase ISO 3166-1 alpha-2. Example: us, br, in
   std::string GetStoredPermanentCountry();
 
   // Forces an override of the stored permanent country. Returns true
   // if the variable has been updated. Return false if the override country is
   // the same as the stored variable, or if the update failed for any other
   // reason.
   bool OverrideStoredPermanentCountry(const std::string& override_country);
 
+  // Returns what variations will consider to be the latest country. Returns
+  // empty if it is not available.
+  std::string GetLatestCountry() const;
+
   // Exposed for testing.
   static std::string GetDefaultVariationsServerURLForTesting();
 
   // Register Variations related prefs in Local State.
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
   // Register Variations related prefs in the Profile prefs.
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
   // Factory method for creating a VariationsService. Does not take ownership of
@@ skipping 190 matching lines @@
   base::ThreadChecker thread_checker_;
 
   base::WeakPtrFactory<VariationsService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VariationsService);
 };
 
 }  // namespace variations
 
 #endif  // COMPONENTS_VARIATIONS_SERVICE_VARIATIONS_SERVICE_H_