api: add some more API to go1.11.txt

Added since last update.

Change-Id: Ic5be0e2e379d422ef72b956a794d65613a0dd7be
Reviewed-on: https://go-review.googlesource.com/122815Reviewed-by: Andrew Bonventre <andybons@golang.org>

api/go1.11.txt

@@ -445,9 +445,19 @@ pkg net, method (*ListenConfig) ListenPacket(context.Context, string, string) (P
 pkg net, type Dialer struct, Control func(string, string, syscall.RawConn) error
 pkg net, type ListenConfig struct
 pkg net, type ListenConfig struct, Control func(string, string, syscall.RawConn) error
+pkg net/http, const SameSiteDefaultMode = 1
+pkg net/http, const SameSiteDefaultMode SameSite
+pkg net/http, const SameSiteLaxMode = 2
+pkg net/http, const SameSiteLaxMode SameSite
+pkg net/http, const SameSiteStrictMode = 3
+pkg net/http, const SameSiteStrictMode SameSite
 pkg net/http, const StatusMisdirectedRequest = 421
 pkg net/http, const StatusMisdirectedRequest ideal-int
+pkg net/http, type Cookie struct, SameSite SameSite
+pkg net/http, type SameSite int
+pkg net/http, type Transport struct, MaxConnsPerHost int
 pkg net/http/httptrace, type ClientTrace struct, Got1xxResponse func(int, textproto.MIMEHeader) error
+pkg net/http/httptrace, type ClientTrace struct, WroteHeaderField func(string, []string)
 pkg os, const ModeIrregular = 524288
 pkg os, const ModeIrregular FileMode
 pkg os, const ModeType = 2399666176