Migrate about:flags messages to const char*

chrome/browser/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 388 matching lines @@
     "favicon/fallback_icon_service_factory.h",
     "favicon/favicon_service_factory.cc",
     "favicon/favicon_service_factory.h",
     "favicon/favicon_utils.cc",
     "favicon/favicon_utils.h",
     "favicon/large_icon_service_factory.cc",
     "favicon/large_icon_service_factory.h",
     "file_select_helper.cc",
     "file_select_helper.h",
     "file_select_helper_mac.mm",
+    "flag_descriptions.cc",
+    "flag_descriptions.h",
     "fullscreen.h",
     "fullscreen_chromeos.cc",
     "fullscreen_mac.mm",
     "fullscreen_win.cc",
     "gcm/gcm_product_util.cc",
     "gcm/gcm_product_util.h",
     "gcm/gcm_profile_service_factory.cc",
     "gcm/gcm_profile_service_factory.h",
     "gcm/instance_id/instance_id_profile_service.cc",
     "gcm/instance_id/instance_id_profile_service.h",
@@ skipping 4194 matching lines @@
       "media/pepper_cdm_test_constants.cc",
       "media/pepper_cdm_test_constants.h",
     ]
   }
 }
 
 service_manifest("preferences_manifest") {
   name = "preferences"
   source = "prefs/preferences_manifest.json"
 }