[Easy Unlock] Update handling of the trial easy unlock/signin run

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index a038deef1fd2c488076076820a3f4473e1695537..568efc92655e6c18815cc77920f84201dbc8238b 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -2341,4 +2341,8 @@ const char kBrowserAddPersonEnabled[] = "profile.add_person_enabled";
 // A dictionary that maps user id to hardlock state.
 const char kEasyUnlockHardlockState[] = "easy_unlock.hardlock_state";
 
+// A dictionary that maps user id to whether the easy unlock has been run for
+// the user.
+const char kEasyUnlockFirstRunComplete[] = "easy_unlock.first_run_complete";
+
 }  // namespace prefs