DevTools: cleanup button styles

third_party/WebKit/Source/devtools/front_end/help/ReleaseNoteView.js

Index: third_party/WebKit/Source/devtools/front_end/help/ReleaseNoteView.js
diff --git a/third_party/WebKit/Source/devtools/front_end/help/ReleaseNoteView.js b/third_party/WebKit/Source/devtools/front_end/help/ReleaseNoteView.js
index a8ab8485f0e3f1622b82d4e720c288c9abeced62..ddd24aaa55fc57c3c4b20298a2a54bc7e24b1989 100644
--- a/third_party/WebKit/Source/devtools/front_end/help/ReleaseNoteView.js
+++ b/third_party/WebKit/Source/devtools/front_end/help/ReleaseNoteView.js
@@ -31,19 +31,14 @@ Help.ReleaseNoteView = class extends UI.VBox {
     }
 
     var actionContainer = container.createChild('div', 'release-note-action-container');
-    var viewMoreButton = actionContainer.createChild('button');
-    viewMoreButton.textContent = Common.UIString('Learn more');
-    viewMoreButton.addEventListener('click', event => {
+    actionContainer.appendChild(UI.createTextButton(Common.UIString('Learn more'), event => {
       event.consume(true);
       InspectorFrontendHost.openInNewTab(releaseNote.link);
-    });
-
-    var closeButton = actionContainer.createChild('button', 'close-release-note');
-    closeButton.textContent = Common.UIString('Close');
-    closeButton.addEventListener('click', event => {
+    }));
+    actionContainer.appendChild(UI.createTextButton(Common.UIString('Close'), event => {
       event.consume(true);
       UI.inspectorView.closeDrawerTab(Help._releaseNoteViewId, true);
-    });
+    }, 'close-release-note'));
 
     var imageLink = UI.createExternalLink(releaseNote.link, ' ');
     imageLink.classList.add('release-note-image');