Add React.PureComponent to documentation

docs/docs/10.8-pure-render-mixin.md

@@ -1,6 +1,6 @@
 ---
 id: pure-render-mixin
-title: PureRenderMixin
+title: PureRenderMixin and React.PureComponent
 permalink: docs/pure-render-mixin.html
 prev: update.html
 next: perf.html
@@ -21,24 +21,18 @@ React.createClass({
 });
 ```
 
-Example using ES6 class syntax:
+Under the hood, the mixin implements [shouldComponentUpdate](/react/docs/component-specs.html#updating-shouldcomponentupdate), in which it compares the current props and state with the next ones and returns `false` if the equalities pass.
 
-```js
-import PureRenderMixin from 'react-addons-pure-render-mixin';
-class FooComponent extends React.Component {
-  constructor(props) {
-    super(props);
-    this.shouldComponentUpdate = PureRenderMixin.shouldComponentUpdate.bind(this);
-  }
+When using ES6 class syntax, you can instead use the `React.PureComponent` base class, which achieves the same result:
 
+```js
+class FooComponent extends React.PureComponent {
   render() {
     return <div className={this.props.className}>foo</div>;
   }
 }
 ```
 
-Under the hood, the mixin implements [shouldComponentUpdate](/react/docs/component-specs.html#updating-shouldcomponentupdate), in which it compares the current props and state with the next ones and returns `false` if the equalities pass.
-
 > Note:
 >
 > This only shallowly compares the objects. If these contain complex data structures, it may produce false-negatives for deeper differences. Only mix into components which have simple props and state, or use `forceUpdate()` when you know deep data structures have changed. Or, consider using [immutable objects](https://facebook.github.io/immutable-js/) to facilitate fast comparisons of nested data.