Add and persist a new field in AlternativeServiceInfo to list QUIC verisons advertised

net/http/http_stream_factory_impl_job_controller.cc

Index: net/http/http_stream_factory_impl_job_controller.cc
diff --git a/net/http/http_stream_factory_impl_job_controller.cc b/net/http/http_stream_factory_impl_job_controller.cc
index 24d6e161d8fa4f8a1e4b82ad5960db385175222d..1823a0bb8ef90a6829a430a1182cb60a045bb55e 100644
--- a/net/http/http_stream_factory_impl_job_controller.cc
+++ b/net/http/http_stream_factory_impl_job_controller.cc
@@ -1151,7 +1151,17 @@ HttpStreamFactoryImpl::JobController::GetAlternativeServiceInfoInternal(
 
     if (session_->quic_stream_factory()->CanUseExistingSession(server_id,
                                                                destination)) {
-      return alternative_service_info;
+      // If advertised versions for QUIC is missing for this
+      // AlternaitverServiceInfo, by default append the list of QUIC versions

[Bence, 2017/06/08 17:44:51]

s/AlternaitverServiceInfo/AlternativeServiceInfo/

[Zhongyi Shi, 2017/06/08 23:11:16]

Acknowledged.

+      // supported by this instance of network stack.
+      first_alternative_service_info = alternative_service_info;
+      if (first_alternative_service_info.alternative_service.protocol ==
+              kProtoQUIC &&
+          first_alternative_service_info.advertised_versions().empty()) {
+        first_alternative_service_info.set_advertised_versions(
+            session_->params().quic_supported_versions);
+      }

[Ryan Hamilton, 2017/06/07 20:52:24]

I wonder if we can get away without this code. If we don't have this, then we'll
end up creating a job with an empty QUIC version vector, right? And that vector
will (eventually) be passed down to the QuicStreamFactory. I think the
QuicStreamFactory would be a good place to apply this logic.

What do you think?

[Zhongyi Shi, 2017/06/08 23:11:16]

Ah good idea! I didn't think about this. But yeah, QuicStreamFactory knows
currently supported versions by Chrome, and should be able to figure out what to
do with an empty list of advertised versions.

+      return first_alternative_service_info;
     }
 
     // Cache this entry if we don't have a non-broken Alt-Svc yet.
@@ -1164,6 +1174,16 @@ HttpStreamFactoryImpl::JobController::GetAlternativeServiceInfoInternal(
   if (quic_advertised && quic_all_broken && delegate != nullptr)
     delegate->OnQuicBroken();
 
+  // If advertised versions for QUIC is missing for this
+  // AlternaitverServiceInfo, by default append the list of QUIC versions
+  // supported by this instance of network stack.
+  if (first_alternative_service_info.alternative_service.protocol ==
+          kProtoQUIC &&
+      first_alternative_service_info.advertised_versions().empty()) {
+    first_alternative_service_info.set_advertised_versions(
+        session_->params().quic_supported_versions);
+  }
+
   return first_alternative_service_info;
 }