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 7dd1abadfb5c98722e6ee59c376b500e5ef1dc93..c7b0a60e0479a379c296fc2414718e5722500c8f 100644
--- a/chrome/browser/profiles/profile.cc
+++ b/chrome/browser/profiles/profile.cc
@@ -175,6 +175,12 @@ 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
 }