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

tracing/tracing/mre/mre_result.html

Index: tracing/tracing/mre/mre_result.html
diff --git a/tracing/tracing/mre/mre_result.html b/tracing/tracing/mre/mre_result.html
index 9df0d204ad6b6b77048c081404cab3356b372db4..e5cc92327791bee89ca9855137a3f25495ddea9e 100644
--- a/tracing/tracing/mre/mre_result.html
+++ b/tracing/tracing/mre/mre_result.html
@@ -12,10 +12,12 @@ found in the LICENSE file.
 tr.exportTo('tr.mre', function() {
   class MreResult {
     constructor(failures, pairs) {
-      if (failures === undefined)
+      if (failures === undefined) {
         failures = [];
-      if (pairs === undefined)
+      }
+      if (pairs === undefined) {
         pairs = {};
+      }
       this.failures = failures;
       this.pairs = pairs;
     }
@@ -25,8 +27,9 @@ tr.exportTo('tr.mre', function() {
     }
 
     addPair(key, value) {
-      if (key in this.pairs)
+      if (key in this.pairs) {
         throw new Error('Key ' + key + ' already exists in result.');
+      }
       this.pairs[key] = value;
     }
 
@@ -35,8 +38,9 @@ tr.exportTo('tr.mre', function() {
         pairs: this.pairs
       };
 
-      if (this.failures)
+      if (this.failures) {
         d.failures = this.failures.map(function(f) {return f.asDict();});
+      }
 
       return d;
     }
@@ -46,8 +50,9 @@ tr.exportTo('tr.mre', function() {
     }
 
     static fromDict(resultDict) {
-      if (resultDict.failures !== undefined)
+      if (resultDict.failures !== undefined) {
         var failures = resultDict.failures.map(tr.mre.Failure.fromDict);
+      }
       var pairs = resultDict.pairs;
       return new MreResult(failures, pairs);
     }