Revert of Remove support for Alt-Svc/Alternate Protocol Probability

net/http/http_server_properties_impl.h

Index: net/http/http_server_properties_impl.h
diff --git a/net/http/http_server_properties_impl.h b/net/http/http_server_properties_impl.h
index d6686733db1f75fe187201d2c908590aa563021a..e42594a42a9c87c10d3ca64e80232504b3de0c01 100644
--- a/net/http/http_server_properties_impl.h
+++ b/net/http/http_server_properties_impl.h
@@ -90,6 +90,7 @@
       const HostPortPair& origin) override;
   bool SetAlternativeService(const HostPortPair& origin,
                              const AlternativeService& alternative_service,
+                             double alternative_probability,
                              base::Time expiration) override;
   bool SetAlternativeServices(const HostPortPair& origin,
                               const AlternativeServiceInfoVector&
@@ -107,6 +108,7 @@
   void ClearAlternativeServices(const HostPortPair& origin) override;
   const AlternativeServiceMap& alternative_service_map() const override;
   scoped_ptr<base::Value> GetAlternativeServiceInfoAsValue() const override;
+  void SetAlternativeServiceProbabilityThreshold(double threshold) override;
   const SettingsMap& GetSpdySettings(
       const HostPortPair& host_port_pair) override;
   bool SetSpdySetting(const HostPortPair& host_port_pair,
@@ -182,6 +184,8 @@
   // ".googlevideo.com", ".googleusercontent.com") of canonical hostnames.
   CanonicalSufficList canonical_suffixes_;
 
+  double alternative_service_probability_threshold_;
+
   QuicServerInfoMap quic_server_info_map_;
   size_t max_server_configs_stored_in_properties_;