Migrate about:flags messages to const char*

ios/chrome/browser/about_flags.mm

Index: ios/chrome/browser/about_flags.mm
diff --git a/ios/chrome/browser/about_flags.mm b/ios/chrome/browser/about_flags.mm
index d29dc0f40d043ea2c96326d9a355c1fd243f81cc..c456d777769bd7f7988cab9a438c6176a277ffe8 100644
--- a/ios/chrome/browser/about_flags.mm
+++ b/ios/chrome/browser/about_flags.mm
@@ -28,6 +28,7 @@
 #include "components/ntp_tiles/switches.h"
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/chrome_switches.h"
+#include "ios/chrome/browser/ios_chrome_flag_descriptions.h"
 #include "ios/chrome/grit/ios_strings.h"
 #include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 #include "ios/web/public/user_agent.h"
@@ -54,16 +55,16 @@ namespace {
 //
 // When adding a new choice, add it to the end of the list.
 const flags_ui::FeatureEntry kFeatureEntries[] = {
-    {"contextual-search", IDS_IOS_FLAGS_CONTEXTUAL_SEARCH,
-     IDS_IOS_FLAGS_CONTEXTUAL_SEARCH_DESCRIPTION, flags_ui::kOsIos,
+    {"contextual-search", flag_descriptions::kContextualSearch,
+     flag_descriptions::kContextualSearchDescription, flags_ui::kOsIos,
      ENABLE_DISABLE_VALUE_TYPE(switches::kEnableContextualSearch,
                                switches::kDisableContextualSearch)},
-    {"ios-physical-web", IDS_IOS_FLAGS_PHYSICAL_WEB,
-     IDS_IOS_FLAGS_PHYSICAL_WEB_DESCRIPTION, flags_ui::kOsIos,
+    {"ios-physical-web", flag_descriptions::kPhysicalWeb,
+     flag_descriptions::kPhysicalWebDescription, flags_ui::kOsIos,
      ENABLE_DISABLE_VALUE_TYPE(switches::kEnableIOSPhysicalWeb,
                                switches::kDisableIOSPhysicalWeb)},
-    {"browser-task-scheduler", IDS_IOS_FLAGS_BROWSER_TASK_SCHEDULER_NAME,
-     IDS_IOS_FLAGS_BROWSER_TASK_SCHEDULER_DESCRIPTION, flags_ui::kOsIos,
+    {"browser-task-scheduler", flag_descriptions::kBrowserTaskScheduler,
+     flag_descriptions::kBrowserTaskSchedulerDescription, flags_ui::kOsIos,
      ENABLE_DISABLE_VALUE_TYPE(switches::kEnableBrowserTaskScheduler,
                                switches::kDisableBrowserTaskScheduler)},
 };