Implement Mail service.

impl/prod/context.go

Index: impl/prod/context.go
diff --git a/impl/prod/context.go b/impl/prod/context.go
index e683051e86df26bb8dbcc4b350ff2ecc51720193..b62614891a0425a3fedc9c91bf5c231427d6b55f 100644
--- a/impl/prod/context.go
+++ b/impl/prod/context.go
@@ -51,13 +51,14 @@ func AEContextNoTxn(c context.Context) context.Context {
 // context.
 //
 // The services added are:
+//   - github.com/luci-go/common/logging
 //   - github.com/luci/gae/service/datastore
-//   - github.com/luci/gae/service/taskqueue
-//   - github.com/luci/gae/service/memcache
 //   - github.com/luci/gae/service/info
+//   - github.com/luci/gae/service/mail
+//   - github.com/luci/gae/service/memcache
+//   - github.com/luci/gae/service/taskqueue
 //   - github.com/luci/gae/service/urlfetch
 //   - github.com/luci/gae/service/user
-//   - github.com/luci-go/common/logging
 //
 // These can be retrieved with the <service>.Get functions.
 //
@@ -66,5 +67,5 @@ func Use(c context.Context, r *http.Request) context.Context {
 	aeCtx := appengine.NewContext(r)
 	c = context.WithValue(c, prodContextKey, aeCtx)
 	c = context.WithValue(c, prodContextNoTxnKey, aeCtx)
-	return useUser(useURLFetch(useRDS(useMC(useTQ(useGI(useLogging(c)))))))
+	return useMail(useUser(useURLFetch(useRDS(useMC(useTQ(useGI(useLogging(c))))))))
 }