Fix problem where field trials using kExpirationYearInFuture could get disabled.

chrome/browser/metrics/variations/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 "chrome/browser/metrics/variations/variations_service.h"
 
 #include <set>
 
 #include "base/base64.h"
 #include "base/build_time.h"
@@ skipping 514 matching lines @@
   base::FieldTrial::Probability total_probability = 0;
   if (!ValidateStudyAndComputeTotalProbability(study, &total_probability))
     return;
 
   // The trial is created without specifying an expiration date because the
   // expiration check in field_trial.cc is based on the build date. Instead,
   // the expiration check using |reference_date| is done explicitly below.
   scoped_refptr<base::FieldTrial> trial(
       base::FieldTrialList::FactoryGetFieldTrial(
           study.name(), total_probability, study.default_experiment_name(),
-          base::FieldTrialList::kExpirationYearInFuture, 1, 1, NULL));
+          base::FieldTrialList::kNoExpirationYear, 1, 1, NULL));
 
   if (study.has_consistency() &&
       study.consistency() == Study_Consistency_PERMANENT) {
     trial->UseOneTimeRandomization();
   }
 
   for (int i = 0; i < study.experiment_size(); ++i) {
     const Study_Experiment& experiment = study.experiment(i);
     if (experiment.name() != study.default_experiment_name())
       trial->AppendGroup(experiment.name(), experiment.probability_weight());
 
     if (experiment.has_experiment_id()) {
       const VariationID variation_id =
           static_cast<VariationID>(experiment.experiment_id());
       AssociateGoogleVariationIDForce(GOOGLE_WEB_PROPERTIES,
                                       study.name(),
                                       experiment.name(),
                                       variation_id);
     }
   }
 
   trial->SetForced();
   if (IsStudyExpired(study, reference_date))
     trial->Disable();
 }
 
 }  // namespace chrome_variations