feedback UI: use native window controls on Mac

chrome/test/data/extensions/api_test/feedback_private/basic/test.js

Index: chrome/test/data/extensions/api_test/feedback_private/basic/test.js
diff --git a/chrome/test/data/extensions/api_test/feedback_private/basic/test.js b/chrome/test/data/extensions/api_test/feedback_private/basic/test.js
index 5512b7eb05e7fa69c8e776d6fc367dc0e6428476..45a0d6e7953e5daf0ead855c091fdf8f16598fd8 100644
--- a/chrome/test/data/extensions/api_test/feedback_private/basic/test.js
+++ b/chrome/test/data/extensions/api_test/feedback_private/basic/test.js
@@ -23,7 +23,8 @@ chrome.test.runTests([
   function sendFeedbackTest() {
     var feedbackInfo = {
       description: 'This is a test description',
-      sendHistograms: false
+      sendHistograms: false,
+      useSystemWindowFrame: false
     };
     chrome.feedbackPrivate.sendFeedback(
         feedbackInfo, chrome.test.callbackPass(function(response) {