Reset java state in jni reset method

Summary: This state was never reset when we switched to doing reset in C instead of re-allocating.

Differential Revision: D4081049

fbshipit-source-id: 0b9ad70339ad906ad5219ad2679329cfe2fd7abc

java/com/facebook/csslayout/CSSNode.java

@@ -72,6 +72,10 @@ public class CSSNode implements CSSNodeAPI<CSSNode> {
     mHasSetMargin = false;
     mHasSetBorder = false;
     mHasSetPosition = false;
+
+    mMeasureFunction = null;
+    mData = null;
+
     jni_CSSNodeReset(mNativePointer);
   }