Revert of Unify enum NextProto and enum AlternateProtocol.

net/http/http_server_properties.h

Index: net/http/http_server_properties.h
diff --git a/net/http/http_server_properties.h b/net/http/http_server_properties.h
index 3733c8672b6b1474e6468afc420b3f123f805d89..eaf0468701c604de19fcfbd4ee0b0b5e1feafb3e 100644
--- a/net/http/http_server_properties.h
+++ b/net/http/http_server_properties.h
@@ -66,17 +66,33 @@
 NET_EXPORT void HistogramBrokenAlternateProtocolLocation(
     BrokenAlternateProtocolLocation location);
 
-NET_EXPORT bool IsAlternateProtocolValid(NextProto protocol);
+enum AlternateProtocol {
+  NPN_HTTP_2,
+  QUIC,
+  UNINITIALIZED_ALTERNATE_PROTOCOL,
+};
+
+NET_EXPORT bool IsAlternateProtocolValid(AlternateProtocol protocol);
+
+NET_EXPORT const char* AlternateProtocolToString(AlternateProtocol protocol);
+NET_EXPORT AlternateProtocol AlternateProtocolFromString(
+    const std::string& str);
+NET_EXPORT_PRIVATE AlternateProtocol AlternateProtocolFromNextProto(
+    NextProto next_proto);
 
 // (protocol, host, port) triple as defined in
 // https://tools.ietf.org/id/draft-ietf-httpbis-alt-svc-06.html
 struct NET_EXPORT AlternativeService {
-  AlternativeService() : protocol(kProtoUnknown), host(), port(0) {}
-
-  AlternativeService(NextProto protocol, const std::string& host, uint16_t port)
+  AlternativeService()
+      : protocol(UNINITIALIZED_ALTERNATE_PROTOCOL), host(), port(0) {}
+
+  AlternativeService(AlternateProtocol protocol,
+                     const std::string& host,
+                     uint16_t port)
       : protocol(protocol), host(host), port(port) {}
 
-  AlternativeService(NextProto protocol, const HostPortPair& host_port_pair)
+  AlternativeService(AlternateProtocol protocol,
+                     const HostPortPair& host_port_pair)
       : protocol(protocol),
         host(host_port_pair.host()),
         port(host_port_pair.port()) {}
@@ -103,7 +119,7 @@
 
   std::string ToString() const;
 
-  NextProto protocol;
+  AlternateProtocol protocol;
   std::string host;
   uint16_t port;
 };
@@ -116,11 +132,12 @@
       : alternative_service(alternative_service),
         expiration(expiration) {}
 
-  AlternativeServiceInfo(NextProto protocol,
+  AlternativeServiceInfo(AlternateProtocol protocol,
                          const std::string& host,
                          uint16_t port,
                          base::Time expiration)
-      : alternative_service(protocol, host, port), expiration(expiration) {}
+      : alternative_service(protocol, host, port),
+        expiration(expiration) {}
 
   AlternativeServiceInfo(
       const AlternativeServiceInfo& alternative_service_info) = default;