Revert of Rollback option put behind the flag.

chromeos/chromeos_switches.cc

Index: chromeos/chromeos_switches.cc
diff --git a/chromeos/chromeos_switches.cc b/chromeos/chromeos_switches.cc
index 77cf81ba93670c963f17511f9aae0f38bc5648fb..6478063d299890b67a0ab737ee7e1c65e428d3d8 100644
--- a/chromeos/chromeos_switches.cc
+++ b/chromeos/chromeos_switches.cc
@@ -89,9 +89,6 @@
 // Enable Kiosk mode for ChromeOS. Note this switch refers to retail mode rather
 // than the kiosk app mode.
 const char kEnableKioskMode[]               = "enable-kiosk-mode";
-
-// Enables rollback option for resetting ChromeOS.
-const char kEnableRollbackOption[]          = "enable-rollback-option";
 
 // Enables request of tablet site (via user agent override).
 const char kEnableRequestTabletSite[]       = "enable-request-tablet-site";