Revert of Unify enum NextProto and enum AlternateProtocol.

net/http/http_server_properties.cc

Index: net/http/http_server_properties.cc
diff --git a/net/http/http_server_properties.cc b/net/http/http_server_properties.cc
index 1e5471c5e0c50be122241a1717a1eeed6645ee8f..c6c6432d5e49c22f6feea3886a91233648024171 100644
--- a/net/http/http_server_properties.cc
+++ b/net/http/http_server_properties.cc
@@ -63,23 +63,66 @@
                             BROKEN_ALTERNATE_PROTOCOL_LOCATION_MAX);
 }
 
-bool IsAlternateProtocolValid(NextProto protocol) {
+bool IsAlternateProtocolValid(AlternateProtocol protocol) {
   switch (protocol) {
-    case kProtoUnknown:
+    case NPN_HTTP_2:
+      return true;
+    case QUIC:
+      return true;
+    case UNINITIALIZED_ALTERNATE_PROTOCOL:
       return false;
-    case kProtoHTTP11:
-      return false;
-    case kProtoHTTP2:
-      return true;
-    case kProtoQUIC:
-      return true;
   }
   NOTREACHED();
   return false;
 }
 
+const char* AlternateProtocolToString(AlternateProtocol protocol) {
+  switch (protocol) {
+    case QUIC:
+      return "quic";
+    case NPN_HTTP_2:
+      return "h2";
+    case UNINITIALIZED_ALTERNATE_PROTOCOL:
+      return "Uninitialized";
+  }
+  NOTREACHED();
+  return "";
+}
+
+AlternateProtocol AlternateProtocolFromString(const std::string& str) {
+  if (str == "quic")
+    return QUIC;
+  if (str == "h2")
+    return NPN_HTTP_2;
+  // "npn-h2" and "npn-spdy/3.1" are accepted here so that persisted settings
+  // with the old string can be loaded from disk.  TODO(bnc):  Remove around
+  // 2016 December.
+  if (str == "npn-h2")
+    return NPN_HTTP_2;
+  if (str == "npn-spdy/3.1")
+    return NPN_HTTP_2;
+
+  return UNINITIALIZED_ALTERNATE_PROTOCOL;
+}
+
+AlternateProtocol AlternateProtocolFromNextProto(NextProto next_proto) {
+  switch (next_proto) {
+    case kProtoHTTP2:
+      return NPN_HTTP_2;
+    case kProtoQUIC:
+      return QUIC;
+
+    case kProtoUnknown:
+    case kProtoHTTP11:
+      break;
+  }
+
+  NOTREACHED() << "Invalid NextProto: " << next_proto;
+  return UNINITIALIZED_ALTERNATE_PROTOCOL;
+}
+
 std::string AlternativeService::ToString() const {
-  return base::StringPrintf("%s %s:%d", NextProtoToString(protocol),
+  return base::StringPrintf("%s %s:%d", AlternateProtocolToString(protocol),
                             host.c_str(), port);
 }