ES6ify /gr-button/*

Bug: Issue 6179
Change-Id: Idffadcf8c181bd1d99987fc5cc1e726c3f0bf260

polygerrit-ui/app/elements/shared/gr-button/gr-button.js

diff --git a/polygerrit-ui/app/elements/shared/gr-button/gr-button.js b/polygerrit-ui/app/elements/shared/gr-button/gr-button.js
index 800b1df..ddb2bc3 100644
--- a/polygerrit-ui/app/elements/shared/gr-button/gr-button.js
+++ b/polygerrit-ui/app/elements/shared/gr-button/gr-button.js
@@ -34,8 +34,8 @@
     },
 
     listeners: {
-      'tap': '_handleAction',
-      'click': '_handleAction',
+      tap: '_handleAction',
+      click: '_handleAction',
     },
 
     behaviors: [
@@ -52,21 +52,21 @@
       'space enter': '_handleCommitKey',
     },
 
-    _handleAction: function(e) {
+    _handleAction(e) {
       if (this.disabled) {
         e.preventDefault();
         e.stopImmediatePropagation();
       }
     },
 
-    _disabledChanged: function(disabled) {
+    _disabledChanged(disabled) {
       if (disabled) {
         this._enabledTabindex = this.getAttribute('tabindex');
       }
       this.setAttribute('tabindex', disabled ? '-1' : this._enabledTabindex);
     },
 
-    _handleCommitKey: function(e) {
+    _handleCommitKey(e) {
       e.preventDefault();
       this.click();
     },

polygerrit-ui/app/elements/shared/gr-button/gr-button_test.html

diff --git a/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.html b/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.html
index c269cb5..536b777 100644
--- a/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.html
+++ b/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.html
@@ -33,63 +33,65 @@
 </test-fixture>
 
 <script>
-  suite('gr-select tests', function() {
-    var element;
-    var sandbox;
+  suite('gr-select tests', () => {
+    let element;
+    let sandbox;
 
-    var addSpyOn = function(eventName) {
-      var spy = sandbox.spy();
+    const addSpyOn = function(eventName) {
+      const spy = sandbox.spy();
       element.addEventListener(eventName, spy);
       return spy;
     };
 
-    setup(function() {
+    setup(() => {
       element = fixture('basic');
       sandbox = sinon.sandbox.create();
     });
 
-    teardown(function() {
+    teardown(() => {
       sandbox.restore();
     });
 
-    ['tap', 'click'].forEach(function(eventName) {
-      test('dispatches ' + eventName + ' event', function() {
-        var spy = addSpyOn(eventName);
+    for (const eventName of ['tap', 'click']) {
+      test('dispatches ' + eventName + ' event', () => {
+        const spy = addSpyOn(eventName);
         MockInteractions.tap(element);
         assert.isTrue(spy.calledOnce);
       });
-    });
+    }
 
     // Keycodes: 32 for Space, 13 for Enter.
-    [32, 13].forEach(function(key) {
-      test('dispatches tap event on keycode ' + key, function() {
-        var tapSpy = sandbox.spy();
+    for (const key of [32, 13]) {
+      test('dispatches tap event on keycode ' + key, () => {
+        const tapSpy = sandbox.spy();
         element.addEventListener('tap', tapSpy);
         MockInteractions.pressAndReleaseKeyOn(element, key);
         assert.isTrue(tapSpy.calledOnce);
-      })});
+      });
+    }
 
-    suite('disabled', function() {
-      setup(function() {
+    suite('disabled', () => {
+      setup(() => {
         element.disabled = true;
       });
 
-      ['tap', 'click'].forEach(function(eventName) {
-        test('stops ' + eventName + ' event', function() {
-          var spy = addSpyOn(eventName);
+      for (const eventName of ['tap', 'click']) {
+        test('stops ' + eventName + ' event', () => {
+          const spy = addSpyOn(eventName);
           MockInteractions.tap(element);
           assert.isFalse(spy.called);
         });
-      });
+      }
 
       // Keycodes: 32 for Space, 13 for Enter.
-      [32, 13].forEach(function(key) {
-        test('stops tap event on keycode ' + key, function() {
-          var tapSpy = sandbox.spy();
+      for (const key of [32, 13]) {
+        test('stops tap event on keycode ' + key, () => {
+          const tapSpy = sandbox.spy();
           element.addEventListener('tap', tapSpy);
           MockInteractions.pressAndReleaseKeyOn(element, key);
           assert.isFalse(tapSpy.called);
-        })});
+        });
+      }
     });
   });
 </script>