Revert of Remove obsolete QUIC disabling code.

net/http/http_network_session.h

Index: net/http/http_network_session.h
diff --git a/net/http/http_network_session.h b/net/http/http_network_session.h
index 4aed6bcff6c7ba35ee606f223f2db6d3a5d8b188..9ae55047c04a2afb35dc5a6a98e7233731c77fb5 100644
--- a/net/http/http_network_session.h
+++ b/net/http/http_network_session.h
@@ -125,6 +125,12 @@
     bool quic_disable_disk_cache;
     // Prefer AES-GCM to ChaCha20 even if no hardware support is present.
     bool quic_prefer_aes;
+    // Specifies the maximum number of connections with high packet loss in
+    // a row after which QUIC will be disabled.
+    int quic_max_number_of_lossy_connections;
+    // Specifies packet loss rate in fraction after which a connection is
+    // closed and is considered as a lossy connection.
+    float quic_packet_loss_threshold;
     // Size in bytes of the QUIC DUP socket receive buffer.
     int quic_socket_receive_buffer_size;
     // Delay starting a TCP connection when QUIC believes it can speak
@@ -149,6 +155,9 @@
     QuicCryptoClientStreamFactory* quic_crypto_client_stream_factory;
     // Versions of QUIC which may be used.
     QuicVersionVector quic_supported_versions;
+    int quic_max_recent_disabled_reasons;
+    int quic_threshold_public_resets_post_handshake;
+    int quic_threshold_timeouts_streams_open;
     // Set of QUIC tags to send in the handshake's connection options.
     QuicTagVector quic_connection_options;
     // If true, all QUIC sessions are closed when any local IP address changes.