Put net.Dialer literal back into godoc

src/net/http/transport.go

@@ -41,8 +41,11 @@ import (
 // as directed by the $HTTP_PROXY and $NO_PROXY (or $http_proxy and
 // $no_proxy) environment variables.
 var DefaultTransport RoundTripper = &Transport{
-	Proxy:                 ProxyFromEnvironment,
-	DialContext:           defaultTransportDialContext(),
+	Proxy: ProxyFromEnvironment,
+	DialContext: defaultTransportDialContext(&net.Dialer{
+		Timeout:   30 * time.Second,
+		KeepAlive: 30 * time.Second,
+	}),
 	ForceAttemptHTTP2:     true,
 	MaxIdleConns:          100,
 	IdleConnTimeout:       90 * time.Second,

src/net/http/transport_default_js.go

@@ -12,6 +12,6 @@ import (
 	"net"
 )
 
-func defaultTransportDialContext() func(context.Context, string, string) (net.Conn, error) {
+func defaultTransportDialContext(dialer *net.Dialer) func(context.Context, string, string) (net.Conn, error) {
 	return nil
 }

src/net/http/transport_default_other.go

@@ -10,13 +10,8 @@ package http
 import (
 	"context"
 	"net"
-	"time"
 )
 
-func defaultTransportDialContext() func(context.Context, string, string) (net.Conn, error) {
-	dialer := &net.Dialer{
-		Timeout:   30 * time.Second,
-		KeepAlive: 30 * time.Second,
-	}
+func defaultTransportDialContext(dialer *net.Dialer) func(context.Context, string, string) (net.Conn, error) {
 	return dialer.DialContext
 }