arc: Prepare ArcAuthEndpoint flag for finch experiment.

chrome/browser/chromeos/arc/arc_auth_service.cc

Index: chrome/browser/chromeos/arc/arc_auth_service.cc
diff --git a/chrome/browser/chromeos/arc/arc_auth_service.cc b/chrome/browser/chromeos/arc/arc_auth_service.cc
index 31145be35a01461e888045cbb613402f0c01067e..0cd4d6f4b4056253cc29d1fccd06a7ac48876691 100644
--- a/chrome/browser/chromeos/arc/arc_auth_service.cc
+++ b/chrome/browser/chromeos/arc/arc_auth_service.cc
@@ -42,6 +42,7 @@
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "components/arc/arc_bridge_service.h"
+#include "components/arc/arc_features.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/pref_service.h"
 #include "components/sync_preferences/pref_service_syncable.h"
@@ -1053,17 +1054,9 @@ void ArcAuthService::OnBackgroundAndroidManagementChecked(
 void ArcAuthService::FetchAuthCode() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
-  const base::CommandLine* command_line =
-      base::CommandLine::ForCurrentProcess();
-  std::string auth_endpoint;
-  if (command_line->HasSwitch(chromeos::switches::kArcUseAuthEndpoint)) {
-    auth_endpoint = command_line->GetSwitchValueASCII(
-        chromeos::switches::kArcUseAuthEndpoint);
-  }
-
-  if (!auth_endpoint.empty()) {
+  if (base::FeatureList::IsEnabled(arc::kArcUseAuthEndpointFeature)) {
     auth_code_fetcher_.reset(new ArcAuthCodeFetcher(
-        this, context_->GetURLRequestContext(), profile_, auth_endpoint));
+        this, context_->GetURLRequestContext(), profile_));
   } else {
     ShowUI(ArcSupportHost::UIPage::LSO_PROGRESS, base::string16());
   }