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

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

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