Use chrome.windows to open chrome://system from Feedback.

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

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /** @type {string}
  * @const
  */
 var FEEDBACK_LANDING_PAGE =
     'https://www.google.com/support/chrome/go/feedback_confirmation';
 /** @type {number}
  * @const
  */
 var MAX_ATTACH_FILE_SIZE = 3 * 1024 * 1024;
 
 var attachedFileBlob = null;
 var lastReader = null;
 
 var feedbackInfo = null;
 var systemInfo = null;
 
+var systemInfoWindowId = 0;
+
 /**
  * Reads the selected file when the user selects a file.
  * @param {Event} fileSelectedEvent The onChanged event for the file input box.
  */
 function onFileSelected(fileSelectedEvent) {
   $('attach-error').hidden = true;
   var file = fileSelectedEvent.target.files[0];
   if (!file) {
     // User canceled file selection.
     attachedFileBlob = null;
@@ skipping 18 matching lines @@
  * attach another file.
  */
 function clearAttachedFile() {
   $('custom-file-container').hidden = true;
   attachedFileBlob = null;
   feedbackInfo.attachedFile = null;
   $('attach-file').hidden = false;
 }
 
 /**
- * Opens a new tab with chrome://system, showing the current system info.
+ * Opens a new window with chrome://system, showing the current system info.
  */
-function openSystemTab() {
-  window.open('chrome://system', '_blank');
+function openSystemInfoWindow() {
+  if (systemInfoWindowId == 0) {
+    chrome.windows.create({url: 'chrome://system'}, function(win) {
+      systemInfoWindowId = win.id;
+      chrome.app.window.current().show();

[xiyuan, 2013/09/16 23:53:45]

Is this necessary? Could you pass focused: true in your createdata to make it
happen?

[rkc, 2013/09/17 00:00:00]

Focused:true I believe is the default. Passing that also has the same result,
the new window comes on top of the feedback window.

I specifically want the new window to be right under my app window so the user
doesn't get confused about where his feedback report went to.

+    });
+  } else {
+    chrome.windows.update(systemInfoWindowId, {drawAttention: true});
+  }
 }
 
 /**
  * Sends the report; after the report is sent, we need to be redirected to
  * the landing page, but we shouldn't be able to navigate back, hence
  * we open the landing page in a new tab and sendReport closes this tab.
  * @return {boolean} True if the report was sent.
  */
 function sendReport() {
   if ($('description-text').value.length == 0) {
@@ skipping 110 matching lines @@
 
   window.addEventListener('DOMContentLoaded', function() {
     // Ready to receive the feedback object.
     chrome.runtime.sendMessage({ready: true});
 
     // Setup our event handlers.
     $('attach-file').addEventListener('change', onFileSelected);
     $('send-report-button').onclick = sendReport;
     $('cancel-button').onclick = cancel;
     $('remove-attached-file').onclick = clearAttachedFile;
+
+    chrome.windows.onRemoved.addListener(function(windowId, removeInfo) {
+      if (windowId == systemInfoWindowId)
+        systemInfoWindowId = 0;
+    });
     if ($('sysinfo-url')) {
-      $('sysinfo-url').onclick = openSystemTab;
+      $('sysinfo-url').onclick = openSystemInfoWindow;
     }
   });
 }
 
 initialize();