Expose privacy-relevant preferences via Chrome's extension API.

chrome/test/data/extensions/api_test/content_settings/persistent_incognito/test.html

-<script>
-// Content settings API test
-// Run with browser_tests --gtest_filter=ExtensionApiTest.PersistentIncognitoContentSettings
-
-var cs = chrome.experimental.contentSettings;
-function expect(expected, message) {
-  return chrome.test.callbackPass(function(value) {
-    chrome.test.assertNoLastError();
-    chrome.test.assertEq(expected, value, message);
-  });
-}
-chrome.test.runTests([
-  function getRegular() {
-    cs.global.thirdPartyCookiesAllowed.get(
-        {},
-        expect({ 'value': true,
-                 'levelOfControl': "controllable_by_this_extension" },
-               "third-party cookies should not be blocked"));
-  },
-  function getIncognito() {
-    cs.global.thirdPartyCookiesAllowed.get(
-        { 'incognito': true },
-        expect({ 'value': true,
-                 'incognitoSpecific': false,
-                 'levelOfControl': "controllable_by_this_extension" },
-               "third-party cookies should not be blocked in incognito mode"));
-  },
-  function set() {
-    cs.global.thirdPartyCookiesAllowed.set(
-        { 'scope': 'incognito_persistent', 'value': false },
-        chrome.test.callbackPass());
-  },
-  function getRegular2() {
-    cs.global.thirdPartyCookiesAllowed.get(
-        {},
-        expect({ 'value': true,
-                 'levelOfControl': "controllable_by_this_extension" },
-               "third-party cookies should not be blocked"));
-  },
-  function getIncognito2() {
-    cs.global.thirdPartyCookiesAllowed.get(
-        { 'incognito': true },
-        expect({ 'value': false,
-                 'incognitoSpecific': true,
-                 'levelOfControl': "controlled_by_this_extension" },
-               "third-party cookies should be blocked in incognito mode"));
-  },
-]);
-</script>