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

tracing/tracing/core/filter.html

Index: tracing/tracing/core/filter.html
diff --git a/tracing/tracing/core/filter.html b/tracing/tracing/core/filter.html
index 99685d21e9a9e86105c85933aea282c3150108ce..cd11d82ed3b3b2466e1d1db34ea0cf13145b622d 100644
--- a/tracing/tracing/core/filter.html
+++ b/tracing/tracing/core/filter.html
@@ -55,15 +55,17 @@ tr.exportTo('tr.c', function() {
     Filter.call(this);
     this.regex_ = makeCaseInsensitiveRegex(text);
 
-    if (!text.length)
+    if (!text.length) {
       throw new Error('Filter text is empty.');
+    }
   }
   TitleOrCategoryFilter.prototype = {
     __proto__: Filter.prototype,
 
     matchSlice: function(slice) {
-      if (slice.title === undefined && slice.category === undefined)
+      if (slice.title === undefined && slice.category === undefined) {
         return false;
+      }
 
       return this.regex_.test(slice.title) ||
           (!!slice.category && this.regex_.test(slice.category));
@@ -77,8 +79,9 @@ tr.exportTo('tr.c', function() {
     Filter.call(this);
     this.text_ = text;
 
-    if (!text.length)
+    if (!text.length) {
       throw new Error('Filter text is empty.');
+    }
   }
   ExactTitleFilter.prototype = {
     __proto__: Filter.prototype,
@@ -104,19 +107,15 @@ tr.exportTo('tr.c', function() {
 
     matchObject_: function(obj) {
       for (var key in obj) {
-        if (!obj.hasOwnProperty(key))
-          continue;
-        if (this.regex_.test(key))
-          return true;
-        if (this.regex_.test(obj[key]))
-          return true;
+        if (!obj.hasOwnProperty(key)) continue;
+        if (this.regex_.test(key)) return true;
+        if (this.regex_.test(obj[key])) return true;
       }
       return false;
     },
 
     matchSlice: function(slice) {
-      if (this.titleOrCategoryFilter_.matchSlice(slice))
-        return true;
+      if (this.titleOrCategoryFilter_.matchSlice(slice)) return true;
       return this.matchObject_(slice.args);
     }
   };