Revert "Refactor current GAE abstraction library to be free of the SDK*"

go/src/infra/gae/libs/wrapper/gae/context.go

Index: go/src/infra/gae/libs/wrapper/gae/context.go
diff --git a/go/src/infra/gae/libs/wrapper/gae/context.go b/go/src/infra/gae/libs/wrapper/gae/context.go
new file mode 100644
index 0000000000000000000000000000000000000000..2bf13f2a14e089975dcb869db606b475307f7baa
--- /dev/null
+++ b/go/src/infra/gae/libs/wrapper/gae/context.go
@@ -0,0 +1,43 @@
+// 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 gae
+
+import (
+	"errors"
+	"golang.org/x/net/context"
+
+	"appengine"
+
+	"github.com/mjibson/goon"
+)
+
+// Use adds implementations for the following gae/wrapper interfaces to the
+// context:
+//   * wrapper.Datastore
+//   * wrapper.TaskQueue
+//   * wrapper.Memcache
+//   * wrapper.GlobalInfo
+//
+// These can be retrieved with the "gae/wrapper".Get functions.
+//
+// The implementations are all backed by the real "appengine" SDK functionality,
+// and by "github.com/mjibson/goon".
+//
+// Using this more than once per context.Context will cause a panic.
+func Use(c context.Context, gaeCtx appengine.Context) context.Context {
+	if c.Value(goonContextKey) != nil {
+		panic(errors.New("gae.Use: called twice on the same Context"))
+	}
+	c = context.WithValue(c, goonContextKey, goon.FromContext(gaeCtx))
+	return useDS(useMC(useTQ(useGI(c))))
+}
+
+type key int
+
+var goonContextKey key
+
+func ctx(c context.Context) *goon.Goon {
+	return c.Value(goonContextKey).(*goon.Goon)
+}