Fix version manager that flip flag in-flight does not make supported versions change.

net/tools/quic/quic_dispatcher.cc

Index: net/tools/quic/quic_dispatcher.cc
diff --git a/net/tools/quic/quic_dispatcher.cc b/net/tools/quic/quic_dispatcher.cc
index b1f351fea104448d7253eded25304171189dcccb..032d8337cb8c6214140f96fc93bbadd65c1750b1 100644
--- a/net/tools/quic/quic_dispatcher.cc
+++ b/net/tools/quic/quic_dispatcher.cc
@@ -311,6 +311,11 @@ bool QuicDispatcher::OnUnauthenticatedPublicHeader(
   QuicVersion version = GetSupportedVersions().front();
   if (header.version_flag) {
     QuicVersion packet_version = header.versions.front();
+    if (FLAGS_quic_fix_version_manager &&
+        framer_.supported_versions() != GetSupportedVersions()) {
+      // Reset framer's version if version flags change in flight.
+      framer_.SetSupportedVersions(GetSupportedVersions());
+    }
     if (!framer_.IsSupportedVersion(packet_version)) {
       if (ShouldCreateSessionForUnknownVersion(framer_.last_version_tag())) {
         return true;