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

tracing/tracing/ui/base/chart_base.html

Index: tracing/tracing/ui/base/chart_base.html
diff --git a/tracing/tracing/ui/base/chart_base.html b/tracing/tracing/ui/base/chart_base.html
index d9470c140246330da6911da708808fe0bdcdc488..6e166d2d3142f0b63864c969f49aeb7ae5d881d1 100644
--- a/tracing/tracing/ui/base/chart_base.html
+++ b/tracing/tracing/ui/base/chart_base.html
@@ -47,8 +47,9 @@ tr.exportTo('tr.ui.b', function() {
 
   function getColorOfKey(key, selected) {
     var id = ColorScheme.getColorIdForGeneralPurposeString(key);
-    if (selected)
+    if (selected) {
       id += ColorScheme.properties.brightenedOffsets[0];
+    }
     return ColorScheme.colorsAsStrings[id];
   }
 
@@ -132,8 +133,9 @@ tr.exportTo('tr.ui.b', function() {
     set enabled(enabled) {
       // If the caller is disabling a data series, but it wasn't optional, then
       // force it to be optional.
-      if (!this.optional && !enabled)
+      if (!this.optional && !enabled) {
         this.optional = true;
+      }
       this.enabled_ = enabled;
     },