Reland "Ensure cookie_controls_mode is set with block_third_party_cookies"

This reland adjusts the PrivacyPageTests cleanup function to ensure all
tests start with a default route of chrome://settings/

Original change's description:
> Ensure cookie_controls_mode is set with block_third_party_cookies
>
> To ensure that the two related preferences, cookie_controls_mode and
> block_third_party_cookies remain in a consistent state, this CL updates
> the existing block_third_party_cookies toggle located in settings
> to update both preferences.
>
> Bug: 1068144
> Change-Id: Ia64cb37c766a3143c6ac986efc67e87283852a8c
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2134261
> Reviewed-by: Christian Dullweber <dullweber@chromium.org>
> Reviewed-by: dpapad <dpapad@chromium.org>
> Commit-Queue: Theodore Olsauskas-Warren <sauski@google.com>
> Cr-Commit-Position: refs/heads/master@{#757019}

Bug: 1068144
Change-Id: Icfe851c8e0300f328e5441393ec3cc4aa8113def
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2141912Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Reviewed-by: dpapad <dpapad@chromium.org>
Commit-Queue: Theodore Olsauskas-Warren <sauski@google.com>
Cr-Commit-Position: refs/heads/master@{#757564}

chrome/browser/resources/settings/privacy_page/BUILD.gn

@@ -563,7 +563,7 @@ polymer_modulizer("privacy_page") {
                    "chrome/browser/resources/settings/metrics_browser_proxy.html|PrivacyElementInteractions,MetricsBrowserProxyImpl",
                    "chrome/browser/resources/settings/privacy_page/privacy_page_browser_proxy.html|PrivacyPageBrowserProxy,PrivacyPageBrowserProxyImpl",
                    "chrome/browser/resources/settings/site_settings/site_settings_prefs_browser_proxy.html|SiteSettingsPrefsBrowserProxyImpl",
-                   "chrome/browser/resources/settings/site_settings/constants.html|ContentSettingsTypes,ChooserType",
+                   "chrome/browser/resources/settings/site_settings/constants.html|ContentSettingsTypes,CookieControlsMode,ChooserType",
                    "chrome/browser/resources/settings/people_page/sync_browser_proxy.html|SyncBrowserProxyImpl,SyncStatus",
                    "chrome/browser/resources/settings/hats_browser_proxy.html|HatsBrowserProxyImpl",
                    "chrome/browser/resources/settings/page_visibility.html|PrivacyPageVisibility",

chrome/browser/resources/settings/privacy_page/privacy_page.html

@@ -273,9 +273,13 @@
               sub-option-mode="cookies-session-only">
           </category-default-setting>
           <settings-toggle-button
+              id="blockThirdPartyCookies"
               pref="{{prefs.profile.block_third_party_cookies}}"
               label="$i18n{thirdPartyCookie}"
-              sub-label="$i18n{thirdPartyCookieSublabel}">
+              sub-label="$i18n{thirdPartyCookieSublabel}"
+              on-settings-boolean-control-change=
+                  "onBlockThirdPartyCookiesToggleChange_"
+              no-set-pref>
           </settings-toggle-button>
           <cr-link-row id="site-data-trigger" class="hr"
               on-click="onSiteDataTap_" label="$i18n{siteSettingsCookieLink}">

chrome/browser/resources/settings/privacy_page/privacy_page.js

@@ -415,6 +415,20 @@ cr.define('settings', function() {
       this.browserProxy_.setBlockAutoplayEnabled(target.checked);
     },
 
+    /**
+     * Updates both required block third party cookie preferences.
+     * @param {!Event} event
+     * @private
+     */
+    onBlockThirdPartyCookiesToggleChange_(event) {
+      const target = /** @type {!SettingsToggleButtonElement} */ (event.target);
+      this.setPrefValue('profile.block_third_party_cookies', target.checked);
+      this.setPrefValue(
+          'profile.cookie_controls_mode',
+          target.checked ? settings.CookieControlsMode.ENABLED :
+                           settings.CookieControlsMode.DISABLED);
+    },
+
     /**
      * Records changes made to the "can a website check if you have saved
      * payment methods" setting for logging, the logic of actually changing the

chrome/test/data/webui/settings/privacy_page_test.js

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 // clang-format off
-// #import {SiteSettingsPrefsBrowserProxyImpl} from 'chrome://settings/lazy_load.js';
+// #import {CookieControlsMode, SiteSettingsPrefsBrowserProxyImpl} from 'chrome://settings/lazy_load.js';
 // #import {flush} from 'chrome://resources/polymer/v3_0/polymer/polymer_bundled.min.js';
 // #import {MetricsBrowserProxyImpl, PrivacyElementInteractions, PrivacyPageBrowserProxyImpl, SyncBrowserProxyImpl, HatsBrowserProxyImpl, Router, routes} from 'chrome://settings/settings.js';
 // #import {TestMetricsBrowserProxy} from 'chrome://test/settings/test_metrics_browser_proxy.m.js';
@@ -165,6 +165,7 @@ suite('PrivacyPage', function() {
 
   teardown(function() {
     page.remove();
+    settings.Router.getInstance().navigateTo(settings.routes.BASIC);
   });
 
   test('showClearBrowsingDataDialog', function() {
@@ -226,6 +227,30 @@ suite('PrivacyPage', function() {
           test_util.isChildVisible(page, '#security-keys-subpage-trigger'));
     }
   });
+
+  test('BlockThirdPartyCookiesToggle', async function() {
+    page.prefs.profile.block_third_party_cookies = {value: false};
+    page.prefs.profile.cookie_controls_mode = {
+      value: settings.CookieControlsMode.DISABLED
+    };
+    settings.Router.getInstance().navigateTo(
+        settings.routes.SITE_SETTINGS_COOKIES);
+    Polymer.dom.flush();
+
+    page.$$('#blockThirdPartyCookies').click();
+    Polymer.dom.flush();
+    assertTrue(page.prefs.profile.block_third_party_cookies.value);
+    assertEquals(
+        page.prefs.profile.cookie_controls_mode.value,
+        settings.CookieControlsMode.ENABLED);
+
+    page.$$('#blockThirdPartyCookies').click();
+    Polymer.dom.flush();
+    assertFalse(page.prefs.profile.block_third_party_cookies.value);
+    assertEquals(
+        page.prefs.profile.cookie_controls_mode.value,
+        settings.CookieControlsMode.DISABLED);
+  });
 });
 
 suite('PrivacyPageRedesignEnabled', function() {