Add support for context-aware cloning functions

Summary:
@public

Context-aware cloning functions are an internal Yoga feature that will be used for Yoga’s JNI code.

It will be possible to specify a context when calculating layout, which will be passed on to cloning functions. This will be a private feature.

Reviewed By: SidharthGuglani

Differential Revision: D14149470

fbshipit-source-id: 1d11106e65f9d872d10f191763da001f8d158a61

yoga/YGConfig.cpp

@@ -25,10 +25,16 @@ void YGConfig::log(
   }
 }
 
-YGNodeRef YGConfig::cloneNode(YGNodeRef node, YGNodeRef owner, int childIndex) {
+YGNodeRef YGConfig::cloneNode(
+    YGNodeRef node,
+    YGNodeRef owner,
+    int childIndex,
+    void* cloneContext) {
   YGNodeRef clone = nullptr;
-  if (cloneNodeCallback_ != nullptr) {
-    clone = cloneNodeCallback_(node, owner, childIndex);
+  if (cloneNodeCallback_.noContext != nullptr) {
+    clone = cloneNodeUsesContext_
+        ? cloneNodeCallback_.withContext(node, owner, childIndex, cloneContext)
+        : cloneNodeCallback_.noContext(node, owner, childIndex);
   }
   if (clone == nullptr) {
     clone = YGNodeClone(node);