[Breakpoint] use PureComponent (firefox-devtools#6583)

bomsy · jbhoosreddy · commit 1840902f91bb · 2018-06-30T17:04:59.000-04:00
diff --git a/src/components/Editor/Breakpoint.js b/src/components/Editor/Breakpoint.js
@@ -4,7 +4,7 @@
 
 // @flow
 
-import React, { Component } from "react";
+import React, { PureComponent } from "react";
 import ReactDOM from "react-dom";
 import classnames from "classnames";
 import Svg from "../shared/Svg";
@@ -33,13 +33,9 @@ type Props = {
   editor: Object
 };
 
-class Breakpoint extends Component<Props> {
+class Breakpoint extends PureComponent<Props> {
   addBreakpoint: Function;
 
-  constructor() {
-    super();
-  }
-
   addBreakpoint = () => {
     const { breakpoint, editor, selectedSource } = this.props;
 
