[ios] Support IncognitoModeAvailability policy on bling

IncognitoModeAvailability enterprise policy specifies whether the user
may open pages in Incognito mode in Google Chrome.

When the policy is unset or set to 0(available), pages may be opened
in Incognito mode. When the policy is set to 1(disabled), pages may not
be opened in Incognito mode. When the policy is set to 2(forced), pages
may be opened ONLY in Incognito mode.

Bug: 1148825
Change-Id: Ia3c4b619289c537b05d565d8c3302c8790df87db
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2553149Reviewed-by: Sergio Collazos <sczs@chromium.org>
Reviewed-by: Owen Min <zmin@chromium.org>
Commit-Queue: Tina Wang <tinazwang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#830568}

chrome/common/pref_names.cc

@@ -390,7 +390,7 @@ const char kSSLErrorOverrideAllowed[] = "ssl.error_override_allowed";
 
 // Enum that specifies whether Incognito mode is:
 // 0 - Enabled. Default behaviour. Default mode is available on demand.
-// 1 - Disabled. Used cannot browse pages in Incognito mode.
+// 1 - Disabled. User cannot browse pages in Incognito mode.
 // 2 - Forced. All pages/sessions are forced into Incognito.
 const char kIncognitoModeAvailability[] = "incognito.mode_availability";
 

components/policy/resources/policy_templates.json

@@ -1760,6 +1760,7 @@
         'chrome_os:14-',
         'android:30-',
       ],
+      'future_on': [ 'ios' ],
       'features': {
         'dynamic_refresh': True,
         'per_profile': True,

ios/chrome/browser/policy/configuration_policy_handler_list_factory.mm

@@ -60,6 +60,9 @@ const PolicyToPreferenceMapEntry kSimplePolicyMap[] = {
   { policy::key::kDefaultPopupsSetting,
     prefs::kManagedDefaultPopupsSetting,
     base::Value::Type::INTEGER },
+  { policy::key::kIncognitoModeAvailability,
+    prefs::kIncognitoModeAvailability,
+    base::Value::Type::INTEGER },
   { policy::key::kMetricsReportingEnabled,
     metrics::prefs::kMetricsReportingEnabled,
     base::Value::Type::BOOLEAN },

ios/chrome/browser/pref_names.cc

@@ -56,6 +56,12 @@ const char kEnableDoNotTrack[] = "enable_do_not_track";
 // Prefs for persisting HttpServerProperties.
 const char kHttpServerProperties[] = "net.http_server_properties";
 
+// Integer that specifies whether Incognito mode is:
+// 0 - Enabled. Default behaviour. Default mode is available on demand.
+// 1 - Disabled. User cannot browse pages in Incognito mode.
+// 2 - Forced. All pages/sessions are forced into Incognito.
+const char kIncognitoModeAvailability[] = "incognito.mode_availability";
+
 // Caches the folder id of user's position in the bookmark hierarchy navigator.
 const char kIosBookmarkCachedFolderId[] = "ios.bookmark.cached_folder_id";
 

ios/chrome/browser/pref_names.h

@@ -20,6 +20,7 @@ extern const char kDataSaverEnabled[];
 extern const char kDefaultCharset[];
 extern const char kEnableDoNotTrack[];
 extern const char kHttpServerProperties[];
+extern const char kIncognitoModeAvailability[];
 extern const char kIosBookmarkCachedFolderId[];
 extern const char kIosBookmarkCachedTopMostRow[];
 extern const char kIosBookmarkFolderDefault[];

ios/chrome/browser/prefs/browser_prefs.mm

@@ -231,6 +231,9 @@ void RegisterBrowserStatePrefs(user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterIntegerPref(kGCMChannelPollIntervalSeconds, 0);
   registry->RegisterInt64Pref(kGCMChannelLastCheckTime, 0);
 
+  // Register kIncognitoModeAvailability to available.
+  registry->RegisterIntegerPref(prefs::kIncognitoModeAvailability, 0);
+
   registry->RegisterListPref(kInvalidatorSavedInvalidations);
   registry->RegisterStringPref(kInvalidatorInvalidationState, std::string());
   registry->RegisterStringPref(kInvalidatorClientId, std::string());

ios/chrome/test/data/policy/policy_test_cases.json

@@ -308,6 +308,20 @@
     ]
   },
 
+  "IncognitoModeAvailability": {
+    "os": [ "ios" ],
+    "policy_pref_mapping_test": [
+      {
+        "policies": { "IncognitoModeAvailability": 1 },
+        "prefs": { "incognito.mode_availability": {} }
+      },
+      {
+        "policies": { "IncognitoModeAvailability": 2 },
+        "prefs": { "incognito.mode_availability": {} }
+      }
+    ]
+  },
+
   "MetricsReportingEnabled": {
     "os": [ "ios" ],
     "policy_pref_mapping_tests": [