Migrate about:flags messages to const char*

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 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_