Enable web-based sign in flow by default. Can use command line argument

chrome/browser/ui/webui/sync_promo/sync_promo_ui.cc

Index: chrome/browser/ui/webui/sync_promo/sync_promo_ui.cc
diff --git a/chrome/browser/ui/webui/sync_promo/sync_promo_ui.cc b/chrome/browser/ui/webui/sync_promo/sync_promo_ui.cc
index 214f9cca2d90f466ebfca62f48e74b778030fd7e..e9129aae51f2cc0ffc3bad3a2ea46ded3e8fdba7 100644
--- a/chrome/browser/ui/webui/sync_promo/sync_promo_ui.cc
+++ b/chrome/browser/ui/webui/sync_promo/sync_promo_ui.cc
@@ -71,13 +71,6 @@ bool AllowPromoAtStartupForCurrentBrand() {
   return true;
 }
 
-bool UseWebBasedSigninFlow() {
-  const bool use_web_based_singin_flow =
-      CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kUseWebBasedSigninFlow);
-  return use_web_based_singin_flow;
-}
-
 // The Web UI data source for the sync promo page.
 class SyncPromoUIHTMLSource : public ChromeWebUIDataSource {
  public:
@@ -303,3 +296,13 @@ bool SyncPromoUI::GetAutoCloseForSyncPromoURL(const GURL& url) {
   }
   return false;
 }
+
+// static
+bool SyncPromoUI::UseWebBasedSigninFlow() {
+#if defined(ENABLE_ONE_CLICK_SIGNIN)
+  return !CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kUseClientLoginSigninFlow);
+#else
+  return false;
+#endif
+}