Change gae to apache 2 license.

service/datastore/pls_impl.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.
 
 // HEAVILY adapted from github.com/golang/appengine/datastore
 
 package datastore
 
 import (
         "fmt"
         "reflect"
         "strconv"
         "strings"
@@ skipping 658 matching lines @@
                 switch val {
                 case "on", "On", "true":
                         return true, nil
                 case "off", "Off", "false":
                         return false, nil
                 }
                 return nil, fmt.Errorf("Toggle field has bad/missing default, got %q", val)
         }
         return nil, fmt.Errorf("helper: meta field with bad type/value %s/%q", t, val)
 }