Change gae to apache 2 license.

filter/dscache/context.go

-// 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.
+// Copyright 2015 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
 
 package dscache
 
 import (
         ds "github.com/luci/gae/service/datastore"
         "github.com/luci/gae/service/info"
         mc "github.com/luci/gae/service/memcache"
         "github.com/luci/luci-go/common/mathrand"
         "golang.org/x/net/context"
 )
@@ skipping 43 matching lines @@
                         shardsForKey,
                 }
 
                 v := c.Value(dsTxnCacheKey)
                 if v == nil {
                         return &dsCache{ds, sc}
                 }
                 return &dsTxnCache{ds, v.(*dsTxnState), sc}
         })
 }