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

tracing/tracing/ui/tracks/rect_track.html

Index: tracing/tracing/ui/tracks/rect_track.html
diff --git a/tracing/tracing/ui/tracks/rect_track.html b/tracing/tracing/ui/tracks/rect_track.html
index f4120a1689b5c4d870e69762a685b8384d915288..67c944771324f5a70cc2413e0ed2d13e0fed9602 100644
--- a/tracing/tracing/ui/tracks/rect_track.html
+++ b/tracing/tracing/ui/tracks/rect_track.html
@@ -122,8 +122,7 @@ tr.exportTo('tr.ui.tracks', function() {
           this.asyncStyle_);
       ctx.restore();
 
-      if (bounds.height <= 6)
-        return;
+      if (bounds.height <= 6) return;
 
       var fontSize;
       var yOffset;
@@ -146,8 +145,9 @@ tr.exportTo('tr.ui.tracks', function() {
     },
 
     addEventsToTrackMap: function(eventToTrackMap) {
-      if (this.rects_ === undefined || this.rects_ === null)
+      if (this.rects_ === undefined || this.rects_ === null) {
         return;
+      }
 
       this.rects_.forEach(function(rect) {
         rect.addToTrackMap(eventToTrackMap, this);
@@ -186,12 +186,10 @@ tr.exportTo('tr.ui.tracks', function() {
       var index = tr.b.findFirstIndexInArray(this.rects_, function(rect) {
         return rect.modelItem === event;
       });
-      if (index === -1)
-        return false;
+      if (index === -1) return false;
 
       var newIndex = index + offset;
-      if (newIndex < 0 || newIndex >= this.rects_.length)
-        return false;
+      if (newIndex < 0 || newIndex >= this.rects_.length) return false;
 
       this.rects_[newIndex].addToSelection(selection);
       return true;
@@ -203,10 +201,11 @@ tr.exportTo('tr.ui.tracks', function() {
         // we should probably add an addToSelectionIfMatching(selection, filter)
         // method to SelectableItem (#900).
         var modelItem = this.rects_[i].modelItem;
-        if (!modelItem)
-          continue;
-        if (filter.matchSlice(modelItem))
+        if (!modelItem) continue;
+
+        if (filter.matchSlice(modelItem)) {
           selection.push(modelItem);
+        }
       }
     },
 
@@ -219,8 +218,7 @@ tr.exportTo('tr.ui.tracks', function() {
           worldX,
           worldMaxDist);
 
-      if (!rect)
-        return;
+      if (!rect) return;
 
       rect.addToSelection(selection);
     }