Add new mark-non-secure-as options to chrome://flags on iOS

ios/chrome/browser/ios_chrome_flag_descriptions.h

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef IOS_CHROME_BROWSER_IOS_CHROME_FLAG_DESCRIPTIONS_H_
 #define IOS_CHROME_BROWSER_IOS_CHROME_FLAG_DESCRIPTIONS_H_
 
 namespace flag_descriptions {
 
 // Title for the flag to control redirection to the task scheduler.
 extern const char kBrowserTaskScheduler[];
 
 // Description of about:flag option to control redirection to the task
 // scheduler.
 extern const char kBrowserTaskSchedulerDescription[];
 
 // Title for the flag to enable Contextual Search.
 extern const char kContextualSearch[];
 
 // Description for the flag to enable Contextual Search.
 extern const char kContextualSearchDescription[];
 
+// Title, description, and options for the MarkHttpAs setting that controls
+// display of omnibox warnings about non-secure pages.
+extern const char kMarkHttpAsName[];
+extern const char kMarkHttpAsDescription[];
+extern const char kMarkHttpAsDangerous[];
+extern const char kMarkHttpAsNonSecureAfterEditing[];
+extern const char kMarkHttpAsNonSecureWhileIncognito[];
+extern const char kMarkHttpAsNonSecureWhileIncognitoOrEditing[];
+
 // Title for the flag to enable Physical Web in the omnibox.
 extern const char kPhysicalWeb[];
 
 // Description for the flag to enable Physical Web in the omnibox.
 extern const char kPhysicalWebDescription[];
 
 }  // namespace flag_descriptions
 
 #endif  // IOS_CHROME_BROWSER_IOS_CHROME_FLAG_DESCRIPTIONS_H_