go.net/publicsuffix: rename exp/cookiejar as net/http/cookiejar.

R=adg
CC=golang-dev
https://golang.org/cl/7435048

publicsuffix/list.go

@@ -11,8 +11,8 @@ package publicsuffix
 // func PublicSuffix and func EffectiveTLDPlusOne.
 
 import (
-	"exp/cookiejar"
 	"fmt"
+	"net/http/cookiejar"
 	"strings"
 )