Disable setting incognito prefs for extensions for now.

chrome/test/data/extensions/api_test/proxy/individual_remove/test.js

 // Copyright (c) 2011 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.
 
 // proxy api test
 // browser_tests.exe
 //     --gtest_filter=ProxySettingsApiTest.ProxyFixedIndividualRemove
 
 var httpProxy = {
   host: "1.1.1.1"
@@ skipping 22 matching lines @@
 var config = { rules: rules, mode: "fixed_servers" };
 
 chrome.test.runTests([
   // Verify that execution has started to make sure flaky timeouts are not
   // caused by us.
   function verifyTestsHaveStarted() {
     chrome.test.succeed();
   },
   function setIndividualProxies() {
     chrome.experimental.proxy.settings.set(
-        {'value': config, 'incognito': false},
+        {'value': config, 'scope': 'regular'},
         chrome.test.callbackPass());
   },
   function clearProxies() {
     chrome.experimental.proxy.settings.clear(
-        {'incognito': false},
+        {'scope': 'regular'},
         chrome.test.callbackPass());
   }
 ]);