feedback UI: use native window controls on Mac

This CL adds a member to FeedbackInfo which instructs the feedback dialog
to use native window controls and implements support for it in the
feedback dialog's JS.

BUG=553991
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2295793002
Cr-Commit-Position: refs/heads/master@{#415396}

chrome/browser/extensions/api/feedback_private/feedback_private_api.cc

@@ -130,6 +130,11 @@ void FeedbackPrivateAPI::RequestFeedbackForFlow(
       info.trace_id.reset(new int(manager->RequestTrace()));
     }
     info.flow = flow;
+#if defined(OS_MACOSX)
+    info.use_system_window_frame = true;
+#else
+    info.use_system_window_frame = false;
+#endif
 
     std::unique_ptr<base::ListValue> args =
         feedback_private::OnFeedbackRequested::Create(info);

chrome/browser/resources/feedback/js/event_handler.js

@@ -260,7 +260,7 @@ function startFeedbackUI(feedbackInfo) {
     return;
   }
   chrome.app.window.create('html/default.html', {
-      frame: 'none',
+      frame: feedbackInfo.useSystemWindowFrame ? 'chrome' : 'none',
       id: FEEDBACK_DEFAULT_WINDOW_ID,
       width: FEEDBACK_WIDTH,
       height: FEEDBACK_HEIGHT,

chrome/browser/resources/feedback/js/topbar_handlers.js

@@ -6,6 +6,13 @@
  * Setup handlers for the minimize and close topbar buttons.
  */
 function initializeHandlers() {
+  // If this dialog is using system window controls, these elements aren't
+  // needed at all.
+  if (window.feedbackInfo.useSystemWindowFrame) {
+    $('minimize-button').hidden = true;
+    $('close-button').hidden = true;
+    return;
+  }
   $('minimize-button').addEventListener('click', function(e) {
     e.preventDefault();
     chrome.app.window.current().minimize();

chrome/common/extensions/api/feedback_private.idl

@@ -71,6 +71,9 @@ namespace feedbackPrivate {
     // Used internally to store the blob uuid after parameter customization.
     DOMString? attachedFileBlobUuid;
     DOMString? screenshotBlobUuid;
+
+    // Whether to use the system-provided window frame or custom frame controls.
+    boolean useSystemWindowFrame;
   };
 
   // Status of the sending of a feedback report.

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) {