Introduce a new FieldTrialList::IsTrialActive() API.

base/metrics/field_trial.cc

Index: base/metrics/field_trial.cc
diff --git a/base/metrics/field_trial.cc b/base/metrics/field_trial.cc
index 391bfc5f7cdb2976b03e54d9f27c4a7badf33304..3f874d85fe4d669ad11e3ba6727e449747bb556a 100644
--- a/base/metrics/field_trial.cc
+++ b/base/metrics/field_trial.cc
@@ -354,32 +354,39 @@ FieldTrial* FieldTrialList::FactoryGetFieldTrialWithRandomizationSeed(
 }
 
 // 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