yahoo: add Yahoo OAuth2 endpoint

Change-Id: I4587eaf06cd94821052095345bb76b24ba500699
Reviewed-on: https://go-review.googlesource.com/84195
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/yahoo/yahoo.go b/yahoo/yahoo.go
new file mode 100644
index 0000000..9fa78a2
--- /dev/null
+++ b/yahoo/yahoo.go
@@ -0,0 +1,17 @@
+// Copyright 2017 The Go 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 yahoo provides constants for using OAuth2 to access Yahoo.
+package yahoo // import "golang.org/x/oauth2/yahoo"
+
+import (
+	"golang.org/x/oauth2"
+)
+
+// Endpoint is Yahoo's OAuth 2.0 endpoint.
+// See https://developer.yahoo.com/oauth2/guide/
+var Endpoint = oauth2.Endpoint{
+	AuthURL:  "https://api.login.yahoo.com/oauth2/request_auth",
+	TokenURL: "https://api.login.yahoo.com/oauth2/get_token",
+}