Fix race condition when clicks are received on react root view and react context is pending

Reviewed By: astreet

Differential Revision: D3297574

fbshipit-source-id: 27ac81342d19947e9425a845d7ef7c73cc4cf090

ReactAndroid/src/main/java/com/facebook/react/uimanager/events/EventDispatcher.java

@@ -119,9 +119,16 @@ public class EventDispatcher implements LifecycleEventListener {
           event.getEventName(),
           event.getUniqueID());
     }
-    // If the host activity is paused, the frame callback may not be currently
-    // posted. Ensure that it is so that this event gets delivered promptly.
-    mCurrentFrameCallback.maybePostFromNonUI();
+    if (mRCTEventEmitter != null) {
+      // If the host activity is paused, the frame callback may not be currently
+      // posted. Ensure that it is so that this event gets delivered promptly.
+      mCurrentFrameCallback.maybePostFromNonUI();
+    } else {
+      // No JS application has started yet, or resumed. This can happen when a ReactRootView is
+      // added to view hierarchy, but ReactContext creation has not completed yet. In this case, any
+      // touch event dispatch will hit this codepath, and we simply queue them so that they
+      // are dispatched once ReactContext creation completes and JS app is running.
+    }
   }
 
   @Override