md-settings: Added settings for fingerprint unlock.

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 e4db80dd6500fd7fd03265a5c2171cc1e1d71d54..0a9a48498a5d7373254d785624bd3ee667513dd5 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -932,6 +932,10 @@ const char kPinUnlockMinimumLength[] = "pin_unlock_minimum_length";
 const char kPinUnlockMaximumLength[] = "pin_unlock_maximum_length";
 // Boolean pref indicating whether users are allowed to set easy pins.
 const char kPinUnlockWeakPinsAllowed[] = "pin_unlock_weak_pins_allowed";
+
+// Boolean pref indicating whether fingerprint unlock is enabled.
+const char kEnableQuickUnlockFingerprint[] =
+    "settings.enable_quick_unlock_fingerprint";
 #endif  // defined(OS_CHROMEOS)
 
 // A boolean pref set to true if a Home button to open the Home pages should be