Variations seed is pulled from the Java application on the first launch of Chrome

components/variations/service/variations_service.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 "components/variations/service/variations_service.h"
 
+#include <vector>
+
 #include "base/build_time.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_util.h"
 #include "base/sys_info.h"
 #include "base/task_runner_util.h"
 #include "base/timer/elapsed_timer.h"
@@ skipping 264 matching lines @@
       create_trials_from_seed_called_(false),
       initial_request_completed_(false),
       disable_deltas_for_next_request_(false),
       resource_request_allowed_notifier_(notifier.Pass()),
       request_count_(0),
       weak_ptr_factory_(this) {
   DCHECK(client_.get());
   DCHECK(resource_request_allowed_notifier_.get());
 
   resource_request_allowed_notifier_->Init(this);
+  seed_store_.SetVariationsFirstRunSeedCallback(
+      client_->GetVariationsFirstRunSeedCallback());
 }
 
 VariationsService::~VariationsService() {
 }
 
 bool VariationsService::CreateTrialsFromSeed(base::FeatureList* feature_list) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   create_trials_from_seed_called_ = true;
 
@@ skipping 552 matching lines @@
   std::string stored_country;
 
   if (list_value->GetSize() == 2) {
     list_value->GetString(1, &stored_country);
   }
 
   return stored_country;
 }
 
 }  // namespace variations