Move retry and lhttp packages from client/internal to common/.

client/internal/lhttp/utils.go

Index: client/internal/lhttp/utils.go
diff --git a/client/internal/lhttp/utils.go b/client/internal/lhttp/utils.go
deleted file mode 100644
index 222d281d9bbbae94af66d64b05cf11a004f707de..0000000000000000000000000000000000000000
--- a/client/internal/lhttp/utils.go
+++ /dev/null
@@ -1,29 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package lhttp
-
-import (
-	"errors"
-	"net/url"
-	"strings"
-)
-
-// URLToHTTPS ensures the url is https://.
-func URLToHTTPS(s string) (string, error) {
-	u, err := url.Parse(s)
-	if err != nil {
-		return "", err
-	}
-	if u.Scheme != "" && u.Scheme != "https" {
-		return "", errors.New("Only https:// scheme is accepted. It can be omitted.")
-	}
-	if !strings.HasPrefix(s, "https://") {
-		s = "https://" + s
-	}
-	if _, err = url.Parse(s); err != nil {
-		return "", err
-	}
-	return s, nil
-}