[release-branch.go1.2] go-tour: use new socket interface

««« CL 100090043 / a8f927c18a86
go-tour: use new socket interface

LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/100090043
»»»

TBR=rsc
CC=golang-codereviews
https://golang.org/cl/97030044
diff --git a/gotour/local.go b/gotour/local.go
index 647aab6..31cb4d5 100644
--- a/gotour/local.go
+++ b/gotour/local.go
@@ -14,6 +14,7 @@
 	"log"
 	"net"
 	"net/http"
+	"net/url"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -104,6 +105,9 @@
 	http.Handle("/static/", fs)
 	http.Handle("/talks/", fs)
 
+	origin := &url.URL{Scheme: "http", Host: host + ":" + port}
+	http.Handle(socketPath, socket.NewHandler(origin))
+
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		if r.URL.Path == "/" {
 			if err := renderTour(w); err != nil {
@@ -114,8 +118,6 @@
 		http.Error(w, "not found", 404)
 	})
 
-	http.Handle(socketPath, socket.Handler)
-
 	err = serveScripts(filepath.Join(root, "js"), "SocketTransport")
 	if err != nil {
 		log.Fatal(err)