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

tracing/tracing/ui/analysis/single_user_expectation_sub_view.html

Index: tracing/tracing/ui/analysis/single_user_expectation_sub_view.html
diff --git a/tracing/tracing/ui/analysis/single_user_expectation_sub_view.html b/tracing/tracing/ui/analysis/single_user_expectation_sub_view.html
index e0ad590d5b48e6ea459bf420d92ab31552304811..0f8d2d8ec46acac25341fee51cb6b7154583c43f 100644
--- a/tracing/tracing/ui/analysis/single_user_expectation_sub_view.html
+++ b/tracing/tracing/ui/analysis/single_user_expectation_sub_view.html
@@ -55,15 +55,15 @@ Polymer({
     this.$.realView.setSelectionWithoutErrorChecks(selection);
 
     this.$.relatedSamples.selection = selection;
-    if (this.$.relatedSamples.hasRelatedSamples())
+    if (this.$.relatedSamples.hasRelatedSamples()) {
       this.$.events.style.display = '';
-    else
+    } else {
       this.$.events.style.display = 'none';
+    }
   },
 
   get relatedEventsToHighlight() {
-    if (!this.currentSelection_)
-      return undefined;
+    if (!this.currentSelection_) return undefined;
     return tr.b.getOnlyElement(this.currentSelection_).associatedEvents;
   },