Offline pages using NQE 2G Slow

components/previews/previews_experiments.cc

 // Copyright 2016 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/previews/previews_experiments.h"
 
 #include <map>
 #include <string>
 
 #include "base/metrics/field_trial.h"
 #include "base/strings/string_util.h"
 #include "components/variations/variations_associated_data.h"
 
 namespace {
 
 // The group of client-side previews experiments.
 const char kClientSidePreviewsFieldTrial[] = "ClientSidePreviews";
 
 const char kEnabled[] = "Enabled";
 
 // Allow offline pages to show for prohibitively slow networks.
 const char kOfflinePagesSlowNetwork[] = "show_offline_pages";
 
+// The string that corresponds to enabled for the variation param experiments.
+const char kExperimentEnabled[] = "true";
+
 }  // namespace
 
 namespace previews {
 
 bool IsIncludedInClientSidePreviewsExperimentsFieldTrial() {
   // By convention, an experiment in the client-side previews study enables use
   // of at least one client-side previews optimization if its name begins with
   // "Enabled."
   return base::StartsWith(
       base::FieldTrialList::FindFullName(kClientSidePreviewsFieldTrial),
       kEnabled, base::CompareCase::SENSITIVE);
 }
 
 bool IsOfflinePreviewsEnabled() {
   if (!IsIncludedInClientSidePreviewsExperimentsFieldTrial())
     return false;
   std::map<std::string, std::string> experiment_params;
   if (!variations::GetVariationParams(kClientSidePreviewsFieldTrial,
                                       &experiment_params)) {
     return false;
   }
   std::map<std::string, std::string>::const_iterator it =
       experiment_params.find(kOfflinePagesSlowNetwork);
-  return it != experiment_params.end() && it->second == "true";
+  return it != experiment_params.end() && it->second == kExperimentEnabled;
+}
+
+bool EnableOfflinePreviewsForTesting() {
+  std::map<std::string, std::string> params;
+  params[kOfflinePagesSlowNetwork] = kExperimentEnabled;
+  return variations::AssociateVariationParams(kClientSidePreviewsFieldTrial,
+                                              kEnabled, params) &&
+         base::FieldTrialList::CreateFieldTrial(kClientSidePreviewsFieldTrial,
+                                                kEnabled);
 }
 
 }  // namespace previews