Invalidate credentials if the server rejects them.

net/http/http_auth.h

Index: net/http/http_auth.h
diff --git a/net/http/http_auth.h b/net/http/http_auth.h
index ef779a12948ac0b6a2dddf63722e5e6483690cbd..cc147a243df8aca6fe2443f0287f3f8be1091ef8 100644
--- a/net/http/http_auth.h
+++ b/net/http/http_auth.h
@@ -52,6 +52,13 @@ class HttpAuth {
     AUTHORIZATION_RESULT_INVALID,  // The authentication challenge headers are
                                    // poorly formed (the authorization attempt
                                    // itself may have been fine).
+
+    AUTHORIZATION_RESULT_DIFFERENT_REALM,  // The authorization
+                                           // attempt was rejected,
+                                           // but the realm associated
+                                           // with the new challenge
+                                           // is different from the
+                                           // previous attempt.
   };
 
   // Describes where the identity used for authentication came from.