Respect QuicAllowed policy for new streams

net/http/http_network_session.cc

Index: net/http/http_network_session.cc
diff --git a/net/http/http_network_session.cc b/net/http/http_network_session.cc
index 2936e12e5048e5b176db85fc7768bf0e4b7b697c..1e5219ff6c0cdab5d6ef9b504386e9bd7226298b 100644
--- a/net/http/http_network_session.cc
+++ b/net/http/http_network_session.cc
@@ -87,6 +87,7 @@ HttpNetworkSession::Params::Params()
       testing_fixed_http_port(0),
       testing_fixed_https_port(0),
       enable_tcp_fast_open_for_ssl(false),
+      dynamic_shared_params(NULL),

[mmenke, 2016/12/13 18:48:54]

nullptr is now preferred (Feel free to change the others in this list, if you
want, but not needed)

[pmarko, 2016/12/19 21:25:11]

Done.

       enable_spdy_ping_based_connection_checking(true),
       enable_http2(true),
       spdy_session_max_recv_window_size(kSpdySessionMaxRecvWindowSize),
@@ -136,6 +137,19 @@ HttpNetworkSession::Params::Params(const Params& other) = default;
 
 HttpNetworkSession::Params::~Params() {}
 
+bool HttpNetworkSession::Params::enable_quic_for_new_streams() const {
+  return enable_quic && (!dynamic_shared_params ||
+                         dynamic_shared_params->enable_quic_for_new_streams);

[mmenke, 2016/12/13 18:48:54]

I assume we do need both this and enable_quic, and can't just merge them.

[Bence, 2016/12/13 19:24:45]

Correct.  For example, |enable_quic| can be cleared by a command line flag or a
field trial.  In that case, QUIC should not be enabled even if the user policy
changes after HttpNetworkSession initialization.

[pmarko, 2016/12/19 21:25:11]

Reduced to only enable_quic, the logic is now outside the net layer.

+}
+
+HttpNetworkSession::DynamicSharedParams::DynamicSharedParams()
+    : enable_quic_for_new_streams(true) {}
+
+HttpNetworkSession::DynamicSharedParams::DynamicSharedParams(
+    const DynamicSharedParams& other) = default;
+
+HttpNetworkSession::DynamicSharedParams::~DynamicSharedParams() {}
+
 // TODO(mbelshe): Move the socket factories into HttpStreamFactory.
 HttpNetworkSession::HttpNetworkSession(const Params& params)
     : net_log_(params.net_log),
@@ -291,6 +305,8 @@ std::unique_ptr<base::Value> HttpNetworkSession::QuicInfoToValue() const {
   std::unique_ptr<base::DictionaryValue> dict(new base::DictionaryValue());
   dict->Set("sessions", quic_stream_factory_.QuicStreamFactoryInfoToValue());
   dict->SetBoolean("quic_enabled", params_.enable_quic);
+  dict->SetBoolean("quic_enabled_for_new_streams",
+                   params_.enable_quic_for_new_streams());
   dict->SetBoolean("enable_quic_port_selection",
                    params_.enable_quic_port_selection);
   std::unique_ptr<base::ListValue> connection_options(new base::ListValue);
@@ -358,7 +374,7 @@ bool HttpNetworkSession::IsProtocolEnabled(NextProto protocol) const {
     case kProtoHTTP2:
       return params_.enable_http2;
     case kProtoQUIC:
-      return params_.enable_quic;
+      return params_.enable_quic_for_new_streams();

[mmenke, 2016/12/13 18:48:54]

HttpNetworkSession::IsProtocolEnabled() -> enable_quic &&
is_enabled_for_new_streams seems very unexpected to me.  Sorry I didn't notice
this before.  Can we either name functions/values in some internally consistent
manner, or merge the quic values?

[pmarko, 2016/12/19 21:25:11]

Reduced to only enable_quic, the logic is now outside the net layer.

   }
   NOTREACHED();
   return false;