Don't update token balances after tracker is stopped

ui/app/components/token-balance.js

@@ -98,6 +98,10 @@ TokenBalance.prototype.componentDidUpdate = function (nextProps) {
 }
 
 TokenBalance.prototype.updateBalance = function (tokens = []) {
+  if (!this.tracker.running) {
+    return
+  }
+
   const [{ string, symbol }] = tokens
 
   this.setState({

ui/app/components/token-list.js

@@ -158,6 +158,9 @@ TokenList.prototype.componentDidUpdate = function (nextProps) {
 }
 
 TokenList.prototype.updateBalances = function (tokens) {
+  if (!this.tracker.running) {
+    return
+  }
   this.setState({ tokens, isLoading: false })
 }
 

ui/app/helpers/with-token-tracker.js

@@ -75,6 +75,9 @@ const withTokenTracker = WrappedComponent => {
     }
 
     updateBalance (tokens = []) {
+      if (!this.tracker.running) {
+        return
+      }
       const [{ string, symbol }] = tokens
       this.setState({ string, symbol, error: null })
     }