Refactor a bit.

service/info/interface.go

Index: service/info/interface.go
diff --git a/service/info/interface.go b/service/info/interface.go
new file mode 100644
index 0000000000000000000000000000000000000000..dcbb345a7a6c632341ee207178ea1bdc812739d8
--- /dev/null
+++ b/service/info/interface.go
@@ -0,0 +1,35 @@
+// 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 info
+
+import (
+	"time"
+
+	"golang.org/x/net/context"
+)
+
+// Interface is the interface for all of the package methods which normally
+// would be in the 'appengine' package.
+type Interface interface {
+	AppID() string
+	Datacenter() string
+	DefaultVersionHostname() string
+	InstanceID() string
+	IsDevAppServer() bool
+	IsOverQuota(err error) bool
+	IsTimeoutError(err error) bool
+	ModuleHostname(module, version, instance string) (string, error)
+	ModuleName() string
+	RequestID() string
+	ServerSoftware() string
+	ServiceAccount() (string, error)
+	VersionID() string
+
+	Namespace(namespace string) (context.Context, error)
+
+	AccessToken(scopes ...string) (token string, expiry time.Time, err error)
+	PublicCertificates() ([]Certificate, error)
+	SignBytes(bytes []byte) (keyName string, signature []byte, err error)
+}