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

net/tools/quic/quic_dispatcher_test.cc

Index: net/tools/quic/quic_dispatcher_test.cc
diff --git a/net/tools/quic/quic_dispatcher_test.cc b/net/tools/quic/quic_dispatcher_test.cc
index 9e898f56f2da2ae4a237a39b2ce50f7689886225..46a44bb837210782de9249c01e69f554f228e95b 100644
--- a/net/tools/quic/quic_dispatcher_test.cc
+++ b/net/tools/quic/quic_dispatcher_test.cc
@@ -537,6 +537,74 @@ TEST_F(QuicDispatcherTest, TooBigSeqNoPacketToTimeWaitListManager) {
                 QuicDispatcher::kMaxReasonableInitialPacketNumber + 1);
 }
 
+TEST_F(QuicDispatcherTest, SupportedVersionsChangeInFlight) {
+  DCHECK_EQ(3u, arraysize(kSupportedQuicVersions));
+  FLAGS_quic_fix_version_manager = true;
+  FLAGS_quic_enable_version_36_v3 = true;
+  IPEndPoint client_address(Loopback4(), 1);
+  server_address_ = IPEndPoint(Any4(), 5);
+  QuicConnectionId connection_id = 1;
+
+  EXPECT_CALL(*dispatcher_, CreateQuicSession(connection_id, client_address))
+      .Times(0);
+  ProcessPacket(client_address, connection_id, true,
+                static_cast<QuicVersion>(QuicVersionMin() - 1), SerializeCHLO(),
+                PACKET_8BYTE_CONNECTION_ID, PACKET_6BYTE_PACKET_NUMBER, 1);
+  ++connection_id;
+  EXPECT_CALL(*dispatcher_, CreateQuicSession(connection_id, client_address))
+      .WillOnce(testing::Return(CreateSession(
+          dispatcher_.get(), config_, connection_id, client_address,
+          &mock_helper_, &mock_alarm_factory_, &crypto_config_,
+          QuicDispatcherPeer::GetCache(dispatcher_.get()), &session1_)));
+  EXPECT_CALL(*reinterpret_cast<MockQuicConnection*>(session1_->connection()),
+              ProcessUdpPacket(_, _, _))
+      .WillOnce(testing::WithArgs<2>(
+          Invoke(CreateFunctor(&QuicDispatcherTest::ValidatePacket,
+                               base::Unretained(this), connection_id))));
+  ProcessPacket(client_address, connection_id, true, QuicVersionMin(),
+                SerializeCHLO(), PACKET_8BYTE_CONNECTION_ID,
+                PACKET_6BYTE_PACKET_NUMBER, 1);
+  ++connection_id;
+  EXPECT_CALL(*dispatcher_, CreateQuicSession(connection_id, client_address))
+      .WillOnce(testing::Return(CreateSession(
+          dispatcher_.get(), config_, connection_id, client_address,
+          &mock_helper_, &mock_alarm_factory_, &crypto_config_,
+          QuicDispatcherPeer::GetCache(dispatcher_.get()), &session1_)));
+  EXPECT_CALL(*reinterpret_cast<MockQuicConnection*>(session1_->connection()),
+              ProcessUdpPacket(_, _, _))
+      .WillOnce(testing::WithArgs<2>(
+          Invoke(CreateFunctor(&QuicDispatcherTest::ValidatePacket,
+                               base::Unretained(this), connection_id))));
+  ProcessPacket(client_address, connection_id, true, QuicVersionMax(),
+                SerializeCHLO(), PACKET_8BYTE_CONNECTION_ID,
+                PACKET_6BYTE_PACKET_NUMBER, 1);
+  // Turn off version 36.
+  FLAGS_quic_enable_version_36_v3 = false;
+  ++connection_id;
+  EXPECT_CALL(*dispatcher_, CreateQuicSession(connection_id, client_address))
+      .Times(0);
+  ProcessPacket(client_address, connection_id, true, QUIC_VERSION_36,
+                SerializeCHLO(), PACKET_8BYTE_CONNECTION_ID,
+                PACKET_6BYTE_PACKET_NUMBER, 1);
+
+  // Turn on version 36.
+  FLAGS_quic_enable_version_36_v3 = true;
+  ++connection_id;
+  EXPECT_CALL(*dispatcher_, CreateQuicSession(connection_id, client_address))
+      .WillOnce(testing::Return(CreateSession(
+          dispatcher_.get(), config_, connection_id, client_address,
+          &mock_helper_, &mock_alarm_factory_, &crypto_config_,
+          QuicDispatcherPeer::GetCache(dispatcher_.get()), &session1_)));
+  EXPECT_CALL(*reinterpret_cast<MockQuicConnection*>(session1_->connection()),
+              ProcessUdpPacket(_, _, _))
+      .WillOnce(testing::WithArgs<2>(
+          Invoke(CreateFunctor(&QuicDispatcherTest::ValidatePacket,
+                               base::Unretained(this), connection_id))));
+  ProcessPacket(client_address, connection_id, true, QUIC_VERSION_35,
+                SerializeCHLO(), PACKET_8BYTE_CONNECTION_ID,
+                PACKET_6BYTE_PACKET_NUMBER, 1);
+}
+
 // Enables mocking of the handshake-confirmation for stateless rejects.
 class MockQuicCryptoServerStream : public QuicCryptoServerStream {
  public: