Summary:
It was just adding unnecessary complexity. Users should just use standard React perf best practices, like `PureComponent` and `shouldComponentUpdate`.
This should be backwards compatible - existing `shouldItemUpdate` usage will just be ignored and should consider migrating to this pattern:
```
class MyItem extends React.PureComponent {
_onPress = () => {
this.props.onPressItem(this.props.id);
};
render() {
return (
<SomeOtherWidget title={this.props.title} onPress={this._onPress} />
)
}
}
...
_renderItem = ({item}) => (
<MyItem onPressItem={this._onPressItem} title={item.title} id={item.id} />
);
```
Which will automatically prevent re-renders unless the relavent data changes.
Reviewed By: yungsters
Differential Revision: D4730599
fbshipit-source-id: 0f61efe96eb4d95bb3b7c4ec889e3e0e34436e56