chrome: Use stl utilities from the base namespace

chrome/common/variations/child_process_field_trial_syncer.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 "chrome/common/variations/child_process_field_trial_syncer.h"
 
 #include <set>
 #include <utility>
 
 #include "base/base_switches.h"
@@ skipping 24 matching lines @@
       command_line.GetSwitchValueASCII(switches::kForceFieldTrials),
       &initially_active_trials);
   std::set<std::string> initially_active_trials_set;
   for (const auto& entry : initially_active_trials) {
     initially_active_trials_set.insert(std::move(entry.trial_name));
   }
 
   base::FieldTrial::ActiveGroups current_active_trials;
   base::FieldTrialList::GetActiveFieldTrialGroups(&current_active_trials);
   for (const auto& trial : current_active_trials) {
-    if (!ContainsKey(initially_active_trials_set, trial.trial_name))
+    if (!base::ContainsKey(initially_active_trials_set, trial.trial_name))
       observer_->OnFieldTrialGroupFinalized(trial.trial_name, trial.group_name);
   }
 }
 
 void ChildProcessFieldTrialSyncer::OnSetFieldTrialGroup(
     const std::string& trial_name,
     const std::string& group_name) {
   base::FieldTrial* trial =
       base::FieldTrialList::CreateFieldTrial(trial_name, group_name);
   // Ensure the trial is marked as "used" by calling group() on it if it is
   // marked as activated.
   trial->group();
   variations::SetVariationListCrashKeys();
 }
 
 }  // namespace chrome_variations