Fix GS client breakage, remove offset hacks.

common/gcloud/gs/opts.go

Index: common/gcloud/gs/opts.go
diff --git a/common/gcloud/gs/opts.go b/common/gcloud/gs/opts.go
deleted file mode 100644
index 171d52d5c04ad159e826cfa48a7be3a27b961054..0000000000000000000000000000000000000000
--- a/common/gcloud/gs/opts.go
+++ /dev/null
@@ -1,57 +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 gs
-
-import (
-	"fmt"
-	"net/http"
-)
-
-// Options are the set of extra options to apply to the Google Storage request.
-type Options struct {
-	// From is the range request starting index. If >0, the beginning of the
-	// range request will be set.
-	From int64
-	// To is the range request ending index. If >0, the end of the
-	// range request will be set.
-	//
-	// If no From index is set, this will result in a request indexed from the end
-	// of the object.
-	To int64
-}
-
-// gsRoundTripper is an http.RoundTripper implementation that allows us to
-// inject some HTTP headers. It is necessary because the stock Google Storage
-// API doesn't allow access to specific header manipulation.
-//
-// https://cloud.google.com/storage/docs/reference-headers#range
-type gsRoundTripper struct {
-	http.RoundTripper
-	*Options
-}
-
-func (rt *gsRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
-	if req.Header == nil {
-		req.Header = make(http.Header)
-	}
-
-	// Add Range header, if configured.
-	rh := ""
-	switch {
-	case rt.From > 0 && rt.To > 0:
-		rh = fmt.Sprintf("bytes=%d-%d", rt.From, rt.To)
-
-	case rt.From > 0:
-		rh = fmt.Sprintf("bytes=%d-", rt.From)
-
-	case rt.To > 0:
-		rh = fmt.Sprintf("bytes=-%d", rt.To)
-	}
-	if rh != "" {
-		req.Header.Add("Range", rh)
-	}
-
-	return rt.RoundTripper.RoundTrip(req)
-}