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];
```

NoopInternalComponent.prototype = {
  mountComponent: function() {
  },
  receiveComponent: function(element) {
    this._renderedOutput = element;
    this._currentElement = element;
  },
  getNativeNode: function() {
    return undefined;
  },
  unmountComponent: function() {
  },
  getPublicInstance: function() {
    return null;
  },
};
var ShallowComponentWrapper = function(element) {
  this.construct(element);
};
Object.assign(
  ShallowComponentWrapper.prototype,
  ReactCompositeComponent.Mixin, {
    _constructComponent:
      ReactCompositeComponent.Mixin._constructComponentWithoutOwner,
    _instantiateReactComponent: function(element) {
      return new NoopInternalComponent(element);
    },
    _replaceNodeWithMarkup: function() {},
    _renderValidatedComponent:
      ReactCompositeComponent.Mixin