Free memory used in tests to enable use of valgrind

Summary: Its very usefull to be able to run valgrind on the tests and benchmarks. We were previously not freeing test memory so valgrind output was very messy.

Reviewed By: javache

Differential Revision: D3937493

fbshipit-source-id: 23c6970d7769b081575d39de583ba954fc65a397

CSSLayout/CSSLayout.c

@@ -142,6 +142,15 @@ void CSSNodeFree(const CSSNodeRef node) {
   free(node);
 }
 
+void CSSNodeFreeRecursive(const CSSNodeRef root) {
+  while (CSSNodeChildCount(root) > 0) {
+    const CSSNodeRef child = CSSNodeGetChild(root, 0);
+    CSSNodeRemoveChild(root, child);
+    CSSNodeFreeRecursive(child);
+  }
+  CSSNodeFree(root);
+}
+
 void CSSNodeInit(const CSSNodeRef node) {
   node->parent = NULL;
   node->children = CSSNodeListNew(4);