adding vendor

vendor/cloud.google.com/go/internal/cloud.go

@@ -0,0 +1,64 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package internal provides support for the cloud packages.
+//
+// Users should not import this package directly.
+package internal
+
+import (
+	"fmt"
+	"net/http"
+)
+
+const userAgent = "gcloud-golang/0.1"
+
+// Transport is an http.RoundTripper that appends Google Cloud client's
+// user-agent to the original request's user-agent header.
+type Transport struct {
+	// TODO(bradfitz): delete internal.Transport. It's too wrappy for what it does.
+	// Do User-Agent some other way.
+
+	// Base is the actual http.RoundTripper
+	// requests will use. It must not be nil.
+	Base http.RoundTripper
+}
+
+// RoundTrip appends a user-agent to the existing user-agent
+// header and delegates the request to the base http.RoundTripper.
+func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
+	req = cloneRequest(req)
+	ua := req.Header.Get("User-Agent")
+	if ua == "" {
+		ua = userAgent
+	} else {
+		ua = fmt.Sprintf("%s %s", ua, userAgent)
+	}
+	req.Header.Set("User-Agent", ua)
+	return t.Base.RoundTrip(req)
+}
+
+// cloneRequest returns a clone of the provided *http.Request.
+// The clone is a shallow copy of the struct and its Header map.
+func cloneRequest(r *http.Request) *http.Request {
+	// shallow copy of the struct
+	r2 := new(http.Request)
+	*r2 = *r
+	// deep copy of the Header
+	r2.Header = make(http.Header)
+	for k, s := range r.Header {
+		r2.Header[k] = s
+	}
+	return r2
+}