[Signin] Add flag for enabling Multilogin endpoint for AccountReconcilor.

Change-Id: I32ea66dcd6d7466573c0ed143038d9edb241ac86
Reviewed-on: https://chromium-review.googlesource.com/1199763
Commit-Queue: Valeriya Sinevich <[email protected]>
Reviewed-by: David Roger <[email protected]>
Cr-Commit-Position: refs/heads/master@{#588786}
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index a18a70d..6b5cc01 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -1226,6 +1226,10 @@
     "Enable support for using the native notification toasts and notification "
     "center on platforms where these are available.";
 
+const char kUseMultiloginEndpointName[] = "Use Multilogin endpoint.";
+const char kUseMultiloginEndpointDescription[] =
+    "Use Gaia OAuth multilogin for identity consistency.";
+
 #if defined(OS_POSIX)
 const char kNtlmV2EnabledName[] = "Enable NTLMv2 Authentication";
 const char kNtlmV2EnabledDescription[] =