[ESLint] Fix violations when enabling curly rule in eslint.

tracing/tracing/ui/base/name_bar_chart_test.html

Index: tracing/tracing/ui/base/name_bar_chart_test.html
diff --git a/tracing/tracing/ui/base/name_bar_chart_test.html b/tracing/tracing/ui/base/name_bar_chart_test.html
index c7efae7de6fe9ff3c2afeee6a9691af240a56521..732f5a7dec52138891266da64f6b176840d57b07 100644
--- a/tracing/tracing/ui/base/name_bar_chart_test.html
+++ b/tracing/tracing/ui/base/name_bar_chart_test.html
@@ -100,8 +100,8 @@ tr.b.unittest.testSuite(function() {
       updateBrushedRange();
     });
     chart.addEventListener('item-mousemove', function(e) {
-      if (e.button === undefined)
-        return;
+      if (e.button === undefined) return;
+
       currentMouseIndex = e.index;
       updateBrushedRange();
     });