null gating for component tree states

Reviewed By: sebmarkbage

Differential Revision: D4592611

fbshipit-source-id: ab1995e60d411c57fc59978d6d6392031334079e

Libraries/Renderer/src/renderers/native/ReactNativeComponentTree.js

@@ -61,7 +61,7 @@ function getInstanceFromTag(tag) {
 
 function getTagFromInstance(inst) {
   // TODO (bvaughn) Clean up once Stack is deprecated
-  var tag = inst._rootNodeID || inst.stateNode._nativeTag;
+  var tag = inst._rootNodeID || (inst.stateNode && inst.stateNode._nativeTag);
   invariant(tag, 'All native instances should have a tag.');
   return tag;
 }