Introduce a new FieldTrialList::IsTrialActive() API.

base/metrics/field_trial.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 "base/metrics/field_trial.h"
 
 #include <algorithm>
 
 #include "base/build_time.h"
 #include "base/logging.h"
@@ skipping 336 matching lines @@
 
   FieldTrial* field_trial = new FieldTrial(trial_name, total_probability,
                                            default_group_name, entropy_value);
   if (GetBuildTime() > CreateTimeFromParams(year, month, day_of_month))
     field_trial->Disable();
   FieldTrialList::Register(field_trial);
   return field_trial;
 }
 
 // static
-FieldTrial* FieldTrialList::Find(const std::string& name) {
+FieldTrial* FieldTrialList::Find(const std::string& trial_name) {
   if (!global_)
     return NULL;
   AutoLock auto_lock(global_->lock_);
-  return global_->PreLockedFind(name);
+  return global_->PreLockedFind(trial_name);
 }
 
 // static
-int FieldTrialList::FindValue(const std::string& name) {
-  FieldTrial* field_trial = Find(name);
+int FieldTrialList::FindValue(const std::string& trial_name) {
+  FieldTrial* field_trial = Find(trial_name);
   if (field_trial)
     return field_trial->group();
   return FieldTrial::kNotFinalized;
 }
 
 // static
-std::string FieldTrialList::FindFullName(const std::string& name) {
-  FieldTrial* field_trial = Find(name);
+std::string FieldTrialList::FindFullName(const std::string& trial_name) {
+  FieldTrial* field_trial = Find(trial_name);
   if (field_trial)
     return field_trial->group_name();
   return std::string();
 }
 
 // static
-bool FieldTrialList::TrialExists(const std::string& name) {
-  return Find(name) != NULL;
+bool FieldTrialList::TrialExists(const std::string& trial_name) {
+  return Find(trial_name) != NULL;
 }
 
 // static
+bool FieldTrialList::IsTrialActive(const std::string& trial_name) {
+  FieldTrial* field_trial = Find(trial_name);
+  FieldTrial::ActiveGroup active_group;
+  return field_trial && field_trial->GetActiveGroup(&active_group);
+}
+
+// static
 void FieldTrialList::StatesToString(std::string* output) {
   FieldTrial::ActiveGroups active_groups;
   GetActiveFieldTrialGroups(&active_groups);
   for (FieldTrial::ActiveGroups::const_iterator it = active_groups.begin();
        it != active_groups.end(); ++it) {
     DCHECK_EQ(std::string::npos,
               it->trial_name.find(kPersistentStringSeparator));
     DCHECK_EQ(std::string::npos,
               it->group_name.find(kPersistentStringSeparator));
     output->append(it->trial_name);
@@ skipping 187 matching lines @@
     return;
   }
   AutoLock auto_lock(global_->lock_);
   DCHECK(!global_->PreLockedFind(trial->trial_name()));
   trial->AddRef();
   trial->SetTrialRegistered();
   global_->registered_[trial->trial_name()] = trial;
 }
 
 }  // namespace base