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];
```

if (owner) {
    var name = owner.getName();
    if (name) {
      return ' Check the render method of `' + name + '`.';
    }
  }
  return '';
}
function getDisplayName(instance) {
  var element = instance._currentElement;
  if (element == null) {
    return '#empty';
  } else if (typeof element === 'string' || typeof element === 'number') {
    return '#text';
  } else if (typeof element.type === 'string') {
    return element.type;
  } else if (instance.getName) {
    return instance.getName() || 'Unknown';
  } else {
    return element.type.displayName || element.type.name || 'Unknown';
  }
}
/**
 * Check if the type reference is a known internal type. I.e. not a user
 * provided composite type.
 *
 * @param {function} type
 * @return {boolean} Returns true if this is a valid internal type.
 */
function isInternalComponentType(type) {