cros: Added a new function to quick unlock api for checking unfinished pins.

chrome/browser/profiles/profile.cc

Index: chrome/browser/profiles/profile.cc
diff --git a/chrome/browser/profiles/profile.cc b/chrome/browser/profiles/profile.cc
index ce0ced0aaa74e079470e3a385011612f69a83128..4b33e4e3aa6d2f943fb9dad4cab5662dc188bd1d 100644
--- a/chrome/browser/profiles/profile.cc
+++ b/chrome/browser/profiles/profile.cc
@@ -171,6 +171,12 @@ void Profile::RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
 
 #if defined(OS_CHROMEOS)
   registry->RegisterBooleanPref(prefs::kAllowScreenLock, true);
+
+  // Preferences related the lock screen pin unlock.
+  registry->RegisterIntegerPref(prefs::kPinUnlockMinimumLength, 4);
+  // 0 indicates no maximum length for the pin.
+  registry->RegisterIntegerPref(prefs::kPinUnlockMaximumLength, 0);
+  registry->RegisterBooleanPref(prefs::kPinUnlockAllowWeakPins, true);
 #endif
 }