message: front/core/layout/Page: remove page grid
diff: import React, { Component } from 'react';
  -import { withStyles } from '@material-ui/core';
  import { theme } from './PageThemeProvider';
  -const styles = theme => ({
  - root: {
  - display: 'grid',
  - gridTemplateAreas:
  - "'pageHeader pageHeader pageHeader' 'pageSubheader pageSubheader pageSubheader' 'pageNav pageContent pageSidebar'",
  - gridTemplateRows: 'auto auto 1fr',
  - gridTemplateColumns: 'auto 1fr auto',
  - minHeight: '100%',
  - paddingBottom: theme.spacing(3),
  - },
  -});
  -
  export const Theme = React.createContext({});
  class Page extends Component {
  @@ -22,16 +9,10 @@ class Page extends Component {
  };
  render() {
  - const { theme, backgroundColor, classes, children, styles = {}, ...otherProps } = this.props;
  + const { theme, children } = this.props;
  - return (
  - <Theme.Provider value={theme}>
  - <div style={{ backgroundColor, ...styles }} className={classes.root} {...otherProps}>
  - {children}
  - </div>
  - </Theme.Provider>
  - );
  + return <Theme.Provider value={theme}>{children}</Theme.Provider>;
  }
  }
  -export default withStyles(styles)(Page);
  +export default Page;
  