[ios] Add feature flag for incognito mode feature

Add a feature flag to guard the changes for IncognitoModeAvailability
policy related changes.

Bug: 1148838
Change-Id: Ibc563259651424c61e189b9ee74dc5c96135af91
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2555257
Commit-Queue: Tina Wang <tinazwang@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#830642}

chrome/browser/flag-metadata.json

@@ -1719,6 +1719,11 @@
     "owners": [ "stkhapugin", "bling-flags@google.com" ],
     "expiry_milestone": 90
   },
+  {
+    "name": "enable-incognito-mode-availability-ios",
+    "owners": [ "tinazwang", "sebsg" ],
+    "expiry_milestone": 92
+  },
   {
     "name": "enable-incognito-shortcut-on-desktop",
     "owners": [ "rhalavati", "chrome-privacy-core@google.com" ],

ios/chrome/browser/flags/about_flags.mm

@@ -624,6 +624,10 @@ const flags_ui::FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kIncognitoAuthenticationName,
      flag_descriptions::kIncognitoAuthenticationDescription, flags_ui::kOsIos,
      FEATURE_VALUE_TYPE(kIncognitoAuthentication)},
+    {"enable-incognito-mode-availability-ios",
+     flag_descriptions::kEnableIncognitoModeAvailabilityIOSName,
+     flag_descriptions::kEnableIncognitoModeAvailabilityIOSDescription,
+     flags_ui::kOsIos, FEATURE_VALUE_TYPE(kEnableIncognitoModeAvailabilityIOS)},
     {"web-view-native-context-menu",
      flag_descriptions::kWebViewNativeContextMenuName,
      flag_descriptions::kWebViewNativeContextMenuDescription, flags_ui::kOsIos,

ios/chrome/browser/flags/ios_chrome_flag_descriptions.cc

@@ -198,6 +198,12 @@ const char kEnableFullPageScreenshotDescription[] =
     "Enables the option of capturing an entire webpage as a PDF when a "
     "screenshot is taken.";
 
+const char kEnableIncognitoModeAvailabilityIOSName[] =
+    "Enable Incognito Mode Management on IOS ";
+const char kEnableIncognitoModeAvailabilityIOSDescription[] =
+    "Enable the corresponding behaviours and UIs when incognito mode is "
+    "managed by the organization.";
+
 const char kEnableIOSManagedSettingsUIName[] = "Enable IOS Managed Settings UI";
 const char kEnableIOSManagedSettingsUIDescription[] =
     "Enable showing a different UI when the setting is managed by an "

ios/chrome/browser/flags/ios_chrome_flag_descriptions.h

@@ -179,6 +179,10 @@ extern const char kEnableCloseAllTabsConfirmationDescription[];
 extern const char kEnableFullPageScreenshotName[];
 extern const char kEnableFullPageScreenshotDescription[];
 
+// Title and description for the flag to enable incognito mode management.
+extern const char kEnableIncognitoModeAvailabilityIOSName[];
+extern const char kEnableIncognitoModeAvailabilityIOSDescription[];
+
 // Title and description for the flag to enable to show a different UI when the
 // setting is managed by an enterprise policy.
 extern const char kEnableIOSManagedSettingsUIName[];

ios/chrome/browser/policy/policy_features.cc

@@ -18,6 +18,9 @@ const base::Feature kEditBookmarksIOS{"EditBookmarksIOS",
 const base::Feature kManagedBookmarksIOS{"ManagedBookmarksIOS",
                                          base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kEnableIncognitoModeAvailabilityIOS{
+    "EnableIncognitoModeAvailabilityIOS", base::FEATURE_DISABLED_BY_DEFAULT};
+
 const base::Feature kURLBlocklistIOS{"URLBlocklistIOS",
                                      base::FEATURE_DISABLED_BY_DEFAULT};
 
@@ -48,6 +51,10 @@ bool IsEnterprisePolicyEnabled() {
   return !IsDisableEnterprisePolicySwitchPresent();
 }
 
+bool IsIncognitoModeAvailable() {
+  return base::FeatureList::IsEnabled(kEnableIncognitoModeAvailabilityIOS);
+}
+
 bool ShouldInstallEnterprisePolicyHandlers() {
   return IsEnterprisePolicyEnabled();
 }

ios/chrome/browser/policy/policy_features.h

@@ -15,6 +15,11 @@ extern const base::Feature kManagedBookmarksIOS;
 // Feature flag for supporting the URLBlocklist enterprise policy on iOS.
 extern const base::Feature kURLBlocklistIOS;
 
+// Feature flag for supporting the IncognitoModeAvailability enterprise policy
+// on iOS. To define if the flag is set, using the helper method
+// IsIncognitoModeAvailable().
+extern const base::Feature kEnableIncognitoModeAvailabilityIOS;
+
 // Returns true if the Chrome Browser Cloud Management flow is enabled.
 bool IsChromeBrowserCloudManagementEnabled();
 
@@ -26,6 +31,10 @@ bool IsEditBookmarksIOSEnabled();
 // controlled by |ShouldInstallEnterprisePolicyHandlers()| below.
 bool IsEnterprisePolicyEnabled();
 
+// Returns true if IncognitoModeAvailability enterprise policy is supported on
+// iOS.
+bool IsIncognitoModeAvailable();
+
 // Returns true if enterprise policy handlers should be installed to parse
 // policy data and make it user visible.
 bool ShouldInstallEnterprisePolicyHandlers();