Clean-up parent / owner reference of children during clonning

Summary: This diff cleans up the parent / owner references for children of ReactShadowNode / YogaNode during cloning. The reason of this behavior is to avoid retaining every generation of trees during cloning. This fixes a memory leak detected when running the ProgressBarExample.android.js in catalyst app

Reviewed By: fkgozali

Differential Revision: D8019894

fbshipit-source-id: b0d38f0c836ffec534f64fa1adbd7511ecf3473d

java/com/facebook/yoga/YogaNode.java

@@ -1,8 +1,9 @@
 /*
- * Copyright (c) 2014-present, Facebook, Inc.
+ *  Copyright (c) 2014-present, Facebook, Inc.
+ *
+ *  This source code is licensed under the MIT license found in the LICENSE
+ *  file in the root directory of this source tree.
  *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
  */
 
 package com.facebook.yoga;
@@ -185,6 +186,11 @@ public class YogaNode implements Cloneable {
       clonedYogaNode.mOwner = null;
       clonedYogaNode.mChildren =
           mChildren != null ? (List<YogaNode>) ((ArrayList) mChildren).clone() : null;
+      if (clonedYogaNode.mChildren != null) {
+        for (YogaNode child : clonedYogaNode.mChildren) {
+          child.mOwner = null;
+        }
+      }
       return clonedYogaNode;
     } catch (CloneNotSupportedException ex) {
       // This class implements Cloneable, this should not happen

yoga/Yoga.cpp

@@ -1,8 +1,9 @@
-/**
+/*
- * Copyright (c) 2014-present, Facebook, Inc.
+ *  Copyright (c) 2014-present, Facebook, Inc.
+ *
+ *  This source code is licensed under the MIT license found in the LICENSE
+ *  file in the root directory of this source tree.
  *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
  */
 
 #include "Yoga.h"
@@ -243,6 +244,9 @@ YGNodeRef YGNodeClone(YGNodeRef oldNode) {
       oldNode->getConfig(),
       node != nullptr,
       "Could not allocate memory for node");
+  for (auto &item : oldNode->getChildren()) {
+    item->setOwner(nullptr);
+  }
   gNodeInstanceCount++;
   node->setOwner(nullptr);
   return node;