Expand FeatureList to support FieldTrial association.

base/metrics/field_trial.h

Index: base/metrics/field_trial.h
diff --git a/base/metrics/field_trial.h b/base/metrics/field_trial.h
index 93521288b7af4386a2a370b8b8e8658c852a6c20..d7f67f7e5b4d4b4c833c82bb5f2361937eb17804 100644
--- a/base/metrics/field_trial.h
+++ b/base/metrics/field_trial.h
@@ -149,6 +149,11 @@ class BASE_EXPORT FieldTrial : public RefCounted<FieldTrial> {
   // is used as the group name. This causes a winner to be chosen if none was.
   const std::string& group_name();
 
+  // Finalizes the group choice and returns the chosen group, but does not mark
+  // the trial as active - so its state will not be reported until group_name()
+  // or similar is called.
+  const std::string& GetGroupNameWithoutActivation();
+
   // Set the field trial as forced, meaning that it was setup earlier than
   // the hard coded registration of the field trial to override it.
   // This allows the code that was hard coded to register the field trial to