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

tracing/tracing/model/user_model/user_expectation.html

Index: tracing/tracing/model/user_model/user_expectation.html
diff --git a/tracing/tracing/model/user_model/user_expectation.html b/tracing/tracing/model/user_model/user_expectation.html
index 6641dbac2541f5b10c6b0684307811915cf7c263..5ec70cc0a23d5fc0278fe0fed8bc00e2ca09579e 100644
--- a/tracing/tracing/model/user_model/user_expectation.html
+++ b/tracing/tracing/model/user_model/user_expectation.html
@@ -51,20 +51,23 @@ tr.exportTo('tr.model.um', function() {
 
     computeCompoundEvenSelectionState: function(selection) {
       var cess = CompoundEventSelectionState.NOT_SELECTED;
-      if (selection.contains(this))
+      if (selection.contains(this)) {
         cess |= CompoundEventSelectionState.EVENT_SELECTED;
+      }
 
-      if (this.associatedEvents.intersectionIsEmpty(selection))
+      if (this.associatedEvents.intersectionIsEmpty(selection)) {
         return cess;
+      }
 
       var allContained = this.associatedEvents.every(function(event) {
         return selection.contains(event);
       });
 
-      if (allContained)
+      if (allContained) {
         cess |= CompoundEventSelectionState.ALL_ASSOCIATED_EVENTS_SELECTED;
-      else
+      } else {
         cess |= CompoundEventSelectionState.SOME_ASSOCIATED_EVENTS_SELECTED;
+      }
       return cess;
     },
 
@@ -72,8 +75,9 @@ tr.exportTo('tr.model.um', function() {
     get associatedSamples() {
       var samples = new tr.model.EventSet();
       this.associatedEvents.forEach(function(event) {
-        if (event instanceof tr.model.ThreadSlice)
+        if (event instanceof tr.model.ThreadSlice) {
           samples.addEventSet(event.overlappingSamples);
+        }
       });
       return samples;
     },
@@ -97,8 +101,9 @@ tr.exportTo('tr.model.um', function() {
       // constructor in that prototype object!
       // http://javascript.info/tutorial/constructor
 
-      if (!this.typeInfo_)
+      if (!this.typeInfo_) {
         throw new Error('Unregistered UserExpectation');
+      }
 
       return this.typeInfo_;
     },
@@ -116,8 +121,9 @@ tr.exportTo('tr.model.um', function() {
     },
 
     get title() {
-      if (!this.initiatorType)
+      if (!this.initiatorType) {
         return this.stageTitle;
+      }
 
       return this.initiatorType + ' ' + this.stageTitle;
     },
@@ -128,8 +134,9 @@ tr.exportTo('tr.model.um', function() {
     get totalCpuMs() {
       var cpuMs = 0;
       this.associatedEvents.forEach(function(event) {
-        if (event.cpuSelfTime)
+        if (event.cpuSelfTime) {
           cpuMs += event.cpuSelfTime;
+        }
       });
       return cpuMs;
     }