I was testing latest refactor of PerfTools.
When using printOperations() often (but not always) I get 

```
Uncaught TypeError: Cannot read property 'displayName' of undefined
```

in getOperations() on the line:

```
var {displayName, ownerID} = treeSnapshot[instanceID];
```

return element;
      }
      var node = document.createElement('div');
      element = <div />;
      ReactDOM.render(<Foo />, node);
      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
      ReactNativeOperationHistoryDevtool.clearHistory();
      element = <span />;
      ReactDOM.render(<Foo />, node);
      assertHistoryMatches([{
        instanceID: inst._debugID,
        type: 'replace with',
        payload: 'SPAN',
      }]);
    });
    it('gets ignored if the type has not changed', () => {
      var element;
      function Foo() {
        return element;
      }
      var node = document.createElement('div');
      element = <div />;
      ReactDOM.render(<Foo />, node);
      ReactNativeOperationHistoryDevtool.clearHistory();