Support delta-compressed variations server responses.

chrome/browser/metrics/variations/variations_service_unittest.cc

 // 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.
 
 #include "chrome/browser/metrics/variations/variations_service.h"
 
 #include <vector>
 
 #include "base/base64.h"
 #include "base/json/json_string_value_serializer.h"
@@ skipping 54 matching lines @@
   void DoActualFetch() override {
     if (intercepts_fetch_) {
       fetch_attempted_ = true;
       return;
     }
 
     VariationsService::DoActualFetch();
   }
 
  protected:
-  void StoreSeed(const std::string& seed_data,
+  bool StoreSeed(const std::string& seed_data,
                  const std::string& seed_signature,
-                 const base::Time& date_fetched) override {
+                 const std::string& country_code,
+                 const base::Time& date_fetched,
+                 bool is_delta_compressed) override {
     seed_stored_ = true;
+    return true;
   }
 
  private:
   bool intercepts_fetch_;
   bool fetch_attempted_;
   bool seed_stored_;
 
   DISALLOW_COPY_AND_ASSIGN(TestVariationsService);
 };
 
@@ skipping 438 matching lines @@
         << test.pref_value_before << ", " << test.version << ", "
         << test.latest_country_code;
 
     histogram_tester.ExpectUniqueSample(
         "Variations.LoadPermanentConsistencyCountryResult",
         test.expected_result, 1);
   }
 }
 
 }  // namespace chrome_variations