cc : Move LayerImpl::parent to test properties

cc/layers/layer_impl_test_properties.h

 // Copyright 2016 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.
 
 #ifndef CC_LAYERS_LAYER_IMPL_TEST_PROPERTIES_H_
 #define CC_LAYERS_LAYER_IMPL_TEST_PROPERTIES_H_
 
 #include <set>
 #include <vector>
 
@@ skipping 27 matching lines @@
   LayerPositionConstraint position_constraint;
   gfx::Point3F transform_origin;
   LayerImpl* scroll_parent;
   std::unique_ptr<std::set<LayerImpl*>> scroll_children;
   LayerImpl* clip_parent;
   std::unique_ptr<std::set<LayerImpl*>> clip_children;
   std::vector<std::unique_ptr<CopyOutputRequest>> copy_requests;
   LayerImplList children;
   LayerImpl* mask_layer;
   LayerImpl* replica_layer;
+  LayerImpl* parent;
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_IMPL_TEST_PROPERTIES_H_