Add function to set marker callbacks

Summary:
@public

Adds a function to allow to configure markers. The function is declared in `YGMarker.h`

Reviewed By: SidharthGuglani

Differential Revision: D13819111

fbshipit-source-id: f9158b3d4e5727da4e151c84b523c7c7e8158620

yoga/YGMarker.cpp

@@ -0,0 +1,14 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include "YGMarker.h"
+#include "YGConfig.h"
+
+void YGConfigSetMarkerCallbacks(
+    YGConfigRef config,
+    YGMarkerCallbacks markerCallbacks) {
+  config->markerCallbacks = markerCallbacks;
+}

yoga/YGMarker.h

@@ -11,6 +11,7 @@
 YG_EXTERN_C_BEGIN
 
 typedef struct YGNode* YGNodeRef;
+typedef struct YGConfig* YGConfigRef;
 
 typedef YG_ENUM_BEGIN(YGMarker){
     YGMarkerLayout,
@@ -33,4 +34,6 @@ typedef struct {
   void (*endMarker)(YGMarker, YGNodeRef, YGMarkerData, void* id);
 } YGMarkerCallbacks;
 
+void YGConfigSetMarkerCallbacks(YGConfigRef, YGMarkerCallbacks);
+
 YG_EXTERN_C_END