CreateTrailsFromString function now accepts argument without last separator symbol

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 54b95211470ffc4acc0ea793895de4c939e889ec..05afb9b31744e777fd9bba8f45237779d8fc9758 100644
--- a/base/metrics/field_trial.cc
+++ b/base/metrics/field_trial.cc
@@ -414,8 +414,10 @@ bool FieldTrialList::CreateTrialsFromString(
       return false;
     size_t group_name_end = trials_string.find(kPersistentStringSeparator,
                                                name_end + 1);
-    if (group_name_end == trials_string.npos || name_end + 1 == group_name_end)
+    if (name_end + 1 == group_name_end)
       return false;
+    if (group_name_end == trials_string.npos)
+      group_name_end = trials_string.length();
     std::string name(trials_string, next_item, name_end - next_item);
     std::string group_name(trials_string, name_end + 1,
                            group_name_end - name_end - 1);