cc : Move LayerImpl::parent to test properties

cc/layers/layer_impl.h

Index: cc/layers/layer_impl.h
diff --git a/cc/layers/layer_impl.h b/cc/layers/layer_impl.h
index b0aaa159cbb36ba0caead64c4048036a8adf7b70..7cb036ba5b82d148cae7492cede02fa49d50eb88 100644
--- a/cc/layers/layer_impl.h
+++ b/cc/layers/layer_impl.h
@@ -102,10 +102,8 @@ class CC_EXPORT LayerImpl {
   bool IsActive() const;
 
   // Tree structure.
-  LayerImpl* parent() { return parent_; }
   void AddChild(std::unique_ptr<LayerImpl> child);
   std::unique_ptr<LayerImpl> RemoveChildForTesting(LayerImpl* child);
-  void SetParent(LayerImpl* parent);
 
   void DistributeScroll(ScrollState* scroll_state);
   void ApplyScroll(ScrollState* scroll_state);
@@ -534,9 +532,6 @@ class CC_EXPORT LayerImpl {
 
   virtual const char* LayerTypeAsString() const;
 
-  // Properties internal to LayerImpl
-  LayerImpl* parent_;
-
   // mask_layer_ can be temporarily stolen during tree sync, we need this ID to
   // confirm newly assigned layer is still the previous one
   int mask_layer_id_;