Change QuicStreamRequest::Request() to take a preferred QuicVersion so that

net/quic/chromium/quic_stream_factory.cc

Index: net/quic/chromium/quic_stream_factory.cc
diff --git a/net/quic/chromium/quic_stream_factory.cc b/net/quic/chromium/quic_stream_factory.cc
index c65cced78bb69c9ec9cfe59a7382fdcbd7a507f0..a040b4449b71677f6de5088b87db3d61be986486 100644
--- a/net/quic/chromium/quic_stream_factory.cc
+++ b/net/quic/chromium/quic_stream_factory.cc
@@ -326,6 +326,7 @@ class QuicStreamFactory::CertVerifierJob {
 class QuicStreamFactory::Job {
  public:
   Job(QuicStreamFactory* factory,
+      const QuicVersion& quic_version,
       HostResolver* host_resolver,
       const QuicSessionKey& key,
       bool was_alternative_service_recently_broken,
@@ -366,6 +367,7 @@ class QuicStreamFactory::Job {
   IoState io_state_;
 
   QuicStreamFactory* factory_;
+  QuicVersion quic_version_;
   HostResolver* host_resolver_;
   std::unique_ptr<HostResolver::Request> request_;
   const QuicSessionKey key_;
@@ -383,6 +385,7 @@ class QuicStreamFactory::Job {
 };
 
 QuicStreamFactory::Job::Job(QuicStreamFactory* factory,
+                            const QuicVersion& quic_version,
                             HostResolver* host_resolver,
                             const QuicSessionKey& key,
                             bool was_alternative_service_recently_broken,
@@ -390,6 +393,7 @@ QuicStreamFactory::Job::Job(QuicStreamFactory* factory,
                             const NetLogWithSource& net_log)
     : io_state_(STATE_RESOLVE_HOST),
       factory_(factory),
+      quic_version_(quic_version),
       host_resolver_(host_resolver),
       key_(key),
       cert_verify_flags_(cert_verify_flags),
@@ -508,10 +512,11 @@ int QuicStreamFactory::Job::DoConnect() {
       NetLogEventType::QUIC_STREAM_FACTORY_JOB_CONNECT,
       NetLog::BoolCallback("require_confirmation", require_confirmation));
 
-  int rv =
-      factory_->CreateSession(key_, cert_verify_flags_, require_confirmation,
-                              address_list_, dns_resolution_start_time_,
-                              dns_resolution_end_time_, net_log_, &session_);
+  DCHECK_NE(quic_version_, QUIC_VERSION_UNSUPPORTED);
+  int rv = factory_->CreateSession(
+      key_, quic_version_, cert_verify_flags_, require_confirmation,
+      address_list_, dns_resolution_start_time_, dns_resolution_end_time_,
+      net_log_, &session_);
   if (rv != OK) {
     DCHECK(rv != ERR_IO_PENDING);
     DCHECK(!session_);
@@ -581,6 +586,7 @@ QuicStreamRequest::~QuicStreamRequest() {
 }
 
 int QuicStreamRequest::Request(const HostPortPair& destination,
+                               const QuicVersionVector& advertised_versions,
                                PrivacyMode privacy_mode,
                                int cert_verify_flags,
                                const GURL& url,
@@ -591,8 +597,8 @@ int QuicStreamRequest::Request(const HostPortPair& destination,
   DCHECK(factory_);
   server_id_ = QuicServerId(HostPortPair::FromURL(url), privacy_mode);
 
-  int rv = factory_->Create(server_id_, destination, cert_verify_flags, url,
-                            method, net_log, this);
+  int rv = factory_->Create(server_id_, destination, advertised_versions,
+                            cert_verify_flags, url, method, net_log, this);
   if (rv == ERR_IO_PENDING) {
     net_log_ = net_log;
     callback_ = callback;
@@ -849,6 +855,7 @@ bool QuicStreamFactory::CanUseExistingSession(const QuicServerId& server_id,
 
 int QuicStreamFactory::Create(const QuicServerId& server_id,
                               const HostPortPair& destination,
+                              const QuicVersionVector& advertised_versions,
                               int cert_verify_flags,
                               const GURL& url,
                               QuicStringPiece method,
@@ -926,8 +933,10 @@ int QuicStreamFactory::Create(const QuicServerId& server_id,
   ignore_result(StartCertVerifyJob(server_id, cert_verify_flags, net_log));
 
   QuicSessionKey key(destination, server_id);
+  QuicVersion quic_version = SelectQuicVersion(advertised_versions);
+  DCHECK_NE(quic_version, QUIC_VERSION_UNSUPPORTED);
   std::unique_ptr<Job> job = base::MakeUnique<Job>(
-      this, host_resolver_, key, WasQuicRecentlyBroken(server_id),
+      this, quic_version, host_resolver_, key, WasQuicRecentlyBroken(server_id),
       cert_verify_flags, net_log);
   int rv = job->Run(base::Bind(&QuicStreamFactory::OnJobComplete,
                                base::Unretained(this), job.get()));
@@ -1458,15 +1467,15 @@ int QuicStreamFactory::ConfigureSocket(DatagramClientSocket* socket,
   return OK;
 }
 
-int QuicStreamFactory::CreateSession(
-    const QuicSessionKey& key,
-    int cert_verify_flags,
-    bool require_confirmation,
-    const AddressList& address_list,
-    base::TimeTicks dns_resolution_start_time,
-    base::TimeTicks dns_resolution_end_time,
-    const NetLogWithSource& net_log,
-    QuicChromiumClientSession** session) {
+int QuicStreamFactory::CreateSession(const QuicSessionKey& key,
+                                     const QuicVersion& quic_version,
+                                     int cert_verify_flags,
+                                     bool require_confirmation,
+                                     const AddressList& address_list,
+                                     base::TimeTicks dns_resolution_start_time,
+                                     base::TimeTicks dns_resolution_end_time,
+                                     const NetLogWithSource& net_log,
+                                     QuicChromiumClientSession** session) {
   TRACE_EVENT0(kNetTracingCategory, "QuicStreamFactory::CreateSession");
   IPEndPoint addr = *address_list.begin();
   const QuicServerId& server_id = key.server_id();
@@ -1502,7 +1511,7 @@ int QuicStreamFactory::CreateSession(
   QuicConnection* connection = new QuicConnection(
       connection_id, QuicSocketAddress(QuicSocketAddressImpl(addr)),
       helper_.get(), alarm_factory_.get(), writer, true /* owns_writer */,
-      Perspective::IS_CLIENT, supported_versions_);
+      Perspective::IS_CLIENT, {quic_version});
   connection->set_ping_timeout(ping_timeout_);
   connection->SetMaxPacketLength(max_packet_length_);
 
@@ -1592,6 +1601,20 @@ void QuicStreamFactory::ConfigureInitialRttEstimate(
   SetInitialRttEstimate(base::TimeDelta(), INITIAL_RTT_DEFAULT, config);
 }
 
+QuicVersion QuicStreamFactory::SelectQuicVersion(
+    const QuicVersionVector& advertised_versions) const {
+  if (advertised_versions.empty())
+    return supported_versions_[0];
+
+  for (const QuicVersion& supported : supported_versions_) {
+    for (const QuicVersion& advertised : advertised_versions) {
+      if (supported == advertised)
+        return supported;
+    }
+  }
+  return supported_versions_[0];

[Bence, 2017/06/28 19:08:58]

Optional: add DCHECK(!supported_versions_.empty()); to QuicStreamFactory
constructor.

[Zhongyi Shi, 2017/07/05 23:08:59]

Acknowledged.

+}
+
 const base::TimeDelta* QuicStreamFactory::GetServerNetworkStatsSmoothedRtt(
     const QuicServerId& server_id) const {
   url::SchemeHostPort server("https", server_id.host_port_pair().host(),