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 f16b2a68c3e1c5f4b12d42f1d2b4630becc276e0..80951ea730898c72c37001ff7998b03b07f71192 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -926,6 +926,10 @@ const char kQuickUnlockModeWhitelist[] = "quick_unlock_mode_whitelist";
 // 2 - day. Users will have to enter their password every day.
 // 3 - week. Users will have to enter their password every week.
 const char kQuickUnlockTimeout[] = "quick_unlock_timeout";
+
+// 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