arc: Prepare ArcAuthEndpoint flag for finch experiment.

chromeos/chromeos_switches.cc

Index: chromeos/chromeos_switches.cc
diff --git a/chromeos/chromeos_switches.cc b/chromeos/chromeos_switches.cc
index 70c100a3c2640bf15d5d43deb26e782cde439627..b9bcbcc88c765465a793a199bc7197f555d86063 100644
--- a/chromeos/chromeos_switches.cc
+++ b/chromeos/chromeos_switches.cc
@@ -61,10 +61,6 @@ const char kAppOemManifestFile[] = "app-mode-oem-manifest";
 // Signals the availability of the ARC instance on this device.
 const char kArcAvailable[] = "arc-available";
 
-// Specifies ARC authorization endpoint to enable automatic sign-in in OptIn
-// flow.
-const char kArcUseAuthEndpoint[] = "arc-use-auth-endpoint";
-
 // Screenshot testing: specifies the directoru where artifacts will be stored.
 const char kArtifactsDir[] = "artifacts-dir";