Revert of Unify enum NextProto and enum AlternateProtocol.

net/socket/ssl_client_socket.cc

Index: net/socket/ssl_client_socket.cc
diff --git a/net/socket/ssl_client_socket.cc b/net/socket/ssl_client_socket.cc
index 7c91d2fb7616a559eee17ca171373a03a625b0da..a2e62264ed1868ca9642d43f3a99033a4920e9bd 100644
--- a/net/socket/ssl_client_socket.cc
+++ b/net/socket/ssl_client_socket.cc
@@ -27,6 +27,34 @@
 SSLClientSocket::SSLClientSocket()
     : signed_cert_timestamps_received_(false),
       stapled_ocsp_response_received_(false) {}
+
+// static
+NextProto SSLClientSocket::NextProtoFromString(base::StringPiece proto_string) {
+  if (proto_string == "http1.1" || proto_string == "http/1.1") {
+    return kProtoHTTP11;
+  } else if (proto_string == "h2") {
+    return kProtoHTTP2;
+  } else if (proto_string == "quic/1+spdy/3") {
+    return kProtoQUIC;
+  } else {
+    return kProtoUnknown;
+  }
+}
+
+// static
+const char* SSLClientSocket::NextProtoToString(NextProto next_proto) {
+  switch (next_proto) {
+    case kProtoHTTP11:
+      return "http/1.1";
+    case kProtoHTTP2:
+      return "h2";
+    case kProtoQUIC:
+      return "quic/1+spdy/3";
+    case kProtoUnknown:
+      break;
+  }
+  return "unknown";
+}
 
 // static
 void SSLClientSocket::SetSSLKeyLogFile(