Upgrade to react-router v5 (#25047)

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/mastodon/components/dropdown_menu.jsx

@@ -2,13 +2,16 @@ import PropTypes from 'prop-types';
 import { PureComponent, cloneElement, Children } from 'react';
 
 import classNames from 'classnames';
+import { withRouter } from 'react-router-dom';
 
 import ImmutablePropTypes from 'react-immutable-proptypes';
 
 import { supportsPassiveEvents } from 'detect-passive-events';
 import Overlay from 'react-overlays/Overlay';
 
-import { CircularProgress } from "./circular_progress";
+import { CircularProgress } from 'mastodon/components/circular_progress';
+import { WithRouterPropTypes } from 'mastodon/utils/react_router';
+
 import { IconButton } from './icon_button';
 
 const listenerOptions = supportsPassiveEvents ? { passive: true, capture: true } : true;
@@ -16,10 +19,6 @@ let id = 0;
 
 class DropdownMenu extends PureComponent {
 
-  static contextTypes = {
-    router: PropTypes.object,
-  };
-
   static propTypes = {
     items: PropTypes.oneOfType([PropTypes.array, ImmutablePropTypes.list]).isRequired,
     loading: PropTypes.bool,
@@ -159,11 +158,7 @@ class DropdownMenu extends PureComponent {
 
 }
 
-export default class Dropdown extends PureComponent {
-
-  static contextTypes = {
-    router: PropTypes.object,
-  };
+class Dropdown extends PureComponent {
 
   static propTypes = {
     children: PropTypes.node,
@@ -183,6 +178,7 @@ export default class Dropdown extends PureComponent {
     renderItem: PropTypes.func,
     renderHeader: PropTypes.func,
     onItemClick: PropTypes.func,
+    ...WithRouterPropTypes
   };
 
   static defaultProps = {
@@ -250,7 +246,7 @@ export default class Dropdown extends PureComponent {
       item.action();
     } else if (item && item.to) {
       e.preventDefault();
-      this.context.router.history.push(item.to);
+      this.props.history.push(item.to);
     }
   };
 
@@ -338,3 +334,5 @@ export default class Dropdown extends PureComponent {
   }
 
 }
+
+export default withRouter(Dropdown);