message: perf: render demos only once
diff: @@ -7,10 +7,12 @@ const StyledDemo = styled.iframe`
  border: 0;
  `;
  +const SUPPORTS = check();
  +
  class PatternDemo extends React.Component {
  render() {
  const {props} = this;
  - return props.contents ? (
  + return SUPPORTS ? (
  <StyledDemo srcDoc={props.contents} seamless />
  ) : (
  <StyledDemo src={props.src} seamless />
  @@ -19,3 +21,10 @@ class PatternDemo extends React.Component {
  }
  export default PatternDemo;
  +
  +function check() {
  + if (!global.document) {
  + return false;
  + }
  + return 'srcdoc' in document.createElement('iframe');
  +}
  