Revert "Introduce AncestorThrottle, which will process 'X-Frame-Options' headers."

net/base/net_error_list.h

Index: net/base/net_error_list.h
diff --git a/net/base/net_error_list.h b/net/base/net_error_list.h
index 39b48c660f1040e53066c11fb938d099424d4d31..be1b712cc7eb76c39ef5484d0f100bec97ce0db5 100644
--- a/net/base/net_error_list.h
+++ b/net/base/net_error_list.h
@@ -107,11 +107,6 @@ NET_ERROR(UPLOAD_STREAM_REWIND_NOT_SUPPORTED, -25)
 // been shut down.
 NET_ERROR(CONTEXT_SHUT_DOWN, -26)
 
-// The request failed because the response was delivered along with requirements
-// which are not met ('X-Frame-Options' and 'Content-Security-Policy' ancestor
-// checks, for instance).
-NET_ERROR(BLOCKED_BY_RESPONSE, -27)
-
 // A connection was closed (corresponding to a TCP FIN).
 NET_ERROR(CONNECTION_CLOSED, -100)