[EasyUnlock] Put entire ChromeOS login flow behind a flag.

components/proximity_auth/screenlock_state.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_PROXIMITY_AUTH_SCREENLOCK_STATE_H
 #define COMPONENTS_PROXIMITY_AUTH_SCREENLOCK_STATE_H
 
 namespace proximity_auth {
 
 // Possible user states of the proximity auth feature on the lock or sign-in
 // screen.
 enum class ScreenlockState {
   // Proximity-based authentication is not enabled, or the screen is not
   // locked.
   INACTIVE,
   // Bluetooth is not on.
   NO_BLUETOOTH,
-  // The local device is in process of turning on Bluetooth.
+  // The local device is in process of connecting to the remote device.
   BLUETOOTH_CONNECTING,
   // No phones eligible to unlock the local device can be found.
   NO_PHONE,
   // A phone eligible to unlock the local device is found, but cannot be
   // authenticated.
   PHONE_NOT_AUTHENTICATED,
   // A phone eligible to unlock the local device is found, but it's locked.
   PHONE_LOCKED,
   // A phone eligible to unlock the local device is found, but it does not have
   // a lock screen enabled.
@@ skipping 15 matching lines @@
   // indicating that the phone is (probably) more than 1 foot away, and
   // therefore is not allowed to unlock the device.
   PHONE_LOCKED_AND_TX_POWER_TOO_HIGH,
   // The local device can be unlocked using proximity-based authentication.
   AUTHENTICATED,
 };
 
 }  // namespace proximity_auth
 
 #endif  // COMPONENTS_PROXIMITY_AUTH_SCREENLOCK_STATE_H