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

chrome/browser/signin/easy_unlock_service_signin_chromeos.cc

 // Copyright 2014 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.
 
 #include "chrome/browser/signin/easy_unlock_service_signin_chromeos.h"
 
 #include <stdint.h>
 
 #include "base/base64url.h"
 #include "base/bind.h"
@@ skipping 248 matching lines @@
 void EasyUnlockServiceSignin::SetAutoPairingResult(
     bool success,
     const std::string& error) {
   NOTREACHED();
 }
 
 void EasyUnlockServiceSignin::InitializeInternal() {
   if (chromeos::LoginState::Get()->IsUserLoggedIn())
     return;
 
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          proximity_auth::switches::kEnableBluetoothLowEnergyDiscovery) &&
+      !base::CommandLine::ForCurrentProcess()->HasSwitch(
+          proximity_auth::switches::kEnableChromeOSLogin)) {
+    return;
+  }
+
   service_active_ = true;
 
   chromeos::LoginState::Get()->AddObserver(this);
   proximity_auth::ScreenlockBridge* screenlock_bridge =
       proximity_auth::ScreenlockBridge::Get();
   screenlock_bridge->AddObserver(this);
   if (screenlock_bridge->focused_account_id().is_valid())
     OnFocusedUserChanged(screenlock_bridge->focused_account_id());
 }
 
@@ skipping 184 matching lines @@
   if (!account_id_.is_valid())
     return nullptr;
 
   const auto it = user_data_.find(account_id_);
   if (it == user_data_.end())
     return nullptr;
   if (it->second->state != USER_DATA_STATE_LOADED)
     return nullptr;
   return it->second.get();
 }