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

tracing/tracing/ui/base/radio_picker.html

Index: tracing/tracing/ui/base/radio_picker.html
diff --git a/tracing/tracing/ui/base/radio_picker.html b/tracing/tracing/ui/base/radio_picker.html
index 90edfc9a675542db12fd6b4827790196d41de22c..c19f213c46a5104b8eacdb0968391f217abf275b 100644
--- a/tracing/tracing/ui/base/radio_picker.html
+++ b/tracing/tracing/ui/base/radio_picker.html
@@ -55,10 +55,11 @@ Polymer({
   },
 
   set vertical(vertical) {
-    if (vertical)
+    if (vertical) {
       this.setAttribute('vertical', true);
-    else
+    } else {
       this.removeAttribute('vertical');
+    }
   },
 
   get settingsKey() {
@@ -66,17 +67,16 @@ Polymer({
   },
 
   set settingsKey(settingsKey) {
-    if (!this.needsInit_)
+    if (!this.needsInit_) {
       throw new Error('Already initialized.');
+    }
     this.settingsKey_ = settingsKey;
     this.maybeInit_();
   },
 
   maybeInit_: function() {
-    if (!this.needsInit_)
-      return;
-    if (this.settingsKey_ === undefined)
-      return;
+    if (!this.needsInit_) return;
+    if (this.settingsKey_ === undefined) return;
     this.needsInit_ = false;
     this.select(tr.b.Settings.get(this.settingsKey_));
   },
@@ -84,8 +84,9 @@ Polymer({
   set items(items) {
     this.radioButtons_ = {};
     items.forEach(function(e) {
-      if (e.key in this.radioButtons_)
+      if (e.key in this.radioButtons_) {
         throw new Error(e.key + ' already exists');
+      }
       var radioButton = document.createElement('div');
       var input = document.createElement('input');
       var label = document.createElement('label');
@@ -107,33 +108,37 @@ Polymer({
   },
 
   maybeRenderRadioButtons_: function() {
-    if (!this.isReady_)
-      return;
-    if (this.radioButtons_ === undefined)
-      return;
-    for (var key in this.radioButtons_)
+    if (!this.isReady_) return;
+    if (this.radioButtons_ === undefined) return;
+    for (var key in this.radioButtons_) {
       Polymer.dom(this.$.container).appendChild(
           this.radioButtons_[key].parentElement);
-    if (this.selectedKey_ !== undefined)
+    }
+    if (this.selectedKey_ !== undefined) {
       this.select(this.selectedKey_);
+    }
   },
 
   select: function(key) {
-    if (key === undefined || key === this.selectedKey_)
+    if (key === undefined || key === this.selectedKey_) {
       return;
+    }
     if (this.radioButtons_ === undefined) {
       this.selectedKey_ = key;
       return;
     }
-    if (!(key in this.radioButtons_))
+    if (!(key in this.radioButtons_)) {
       throw new Error(key + ' does not exists');
+    }
     // Unselect the previous radio, update the key & select the new one.
-    if (this.selectedKey_ !== undefined)
+    if (this.selectedKey_ !== undefined) {
       this.radioButtons_[this.selectedKey_].checked = false;
+    }
     this.selectedKey_ = key;
     tr.b.Settings.set(this.settingsKey_, this.selectedKey_);
-    if (this.selectedKey_ !== undefined)
+    if (this.selectedKey_ !== undefined) {
       this.radioButtons_[this.selectedKey_].checked = true;
+    }
 
     this.dispatchEvent(new tr.b.Event('change', false));
   },