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

chrome/browser/signin/easy_unlock_service_signin_chromeos.cc

Index: chrome/browser/signin/easy_unlock_service_signin_chromeos.cc
diff --git a/chrome/browser/signin/easy_unlock_service_signin_chromeos.cc b/chrome/browser/signin/easy_unlock_service_signin_chromeos.cc
index fc71efaa6848bfb8eb039ef278b3b3623ded45a0..3e90a3c250a14c02365c6b30ec995401886ea9db 100644
--- a/chrome/browser/signin/easy_unlock_service_signin_chromeos.cc
+++ b/chrome/browser/signin/easy_unlock_service_signin_chromeos.cc
@@ -266,6 +266,13 @@ 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);