Handle suggested token resolved elsewhere (#8910)

When a suggested token was resolved in a different window, the popup
or notification UI could get stuck with an empty suggested token list,
where either action would throw an error.

This case is now handled by either redirecting or closing the window,
in the popup and notification cases respectively. This check is
performed on both component mount and update.

ui/app/pages/confirm-add-suggested-token/confirm-add-suggested-token.component.js

@@ -3,6 +3,8 @@ import PropTypes from 'prop-types'
 import Button from '../../components/ui/button'
 import Identicon from '../../components/ui/identicon'
 import TokenBalance from '../../components/ui/token-balance'
+import { getEnvironmentType } from '../../../../app/scripts/lib/util'
+import { ENVIRONMENT_TYPE_NOTIFICATION } from '../../../../app/scripts/lib/enums'
 
 export default class ConfirmAddSuggestedToken extends Component {
   static contextTypes = {
@@ -19,9 +21,23 @@ export default class ConfirmAddSuggestedToken extends Component {
   }
 
   componentDidMount () {
+    this._checkPendingTokens()
+  }
+
+  componentDidUpdate () {
+    this._checkPendingTokens()
+  }
+
+  _checkPendingTokens () {
     const { mostRecentOverviewPage, pendingTokens = {}, history } = this.props
 
-    if (Object.keys(pendingTokens).length === 0) {
+    if (Object.keys(pendingTokens).length > 0) {
+      return
+    }
+
+    if (getEnvironmentType() === ENVIRONMENT_TYPE_NOTIFICATION) {
+      global.platform.closeCurrentWindow()
+    } else {
       history.push(mostRecentOverviewPage)
     }
   }