Unify enum NextProto and enum AlternateProtocol.

net/socket/next_proto.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/socket/next_proto.h"
+
+namespace net {
+
+NextProto NextProtoFromString(base::StringPiece proto_string) {
+  if (proto_string == "http1.1" || proto_string == "http/1.1")
+    return kProtoHTTP11;
+  // "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 (proto_string == "h2" || proto_string == "npn-h2" ||
+      proto_string == "npn-spdy/3.1") {
+    return kProtoHTTP2;
+  }
+  if (proto_string == "quic")
+    return kProtoQUIC;
+
+  return kProtoUnknown;
+}
+
+const char* NextProtoToString(NextProto next_proto) {
+  switch (next_proto) {
+    case kProtoHTTP11:
+      return "http/1.1";
+    case kProtoHTTP2:
+      return "h2";
+    case kProtoQUIC:
+      return "quic";
+    case kProtoUnknown:
+      break;
+  }
+  return "unknown";
+}
+
+}  // namespace net