Convert MessageBoxFlags class into an enum.

chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm

Index: chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm b/chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm
index 0defd120e2dc213b7ab99871836546598e396564..7453dbd3aa100cb0506aff9a9bc352ac3102f57e 100644
--- a/chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm
+++ b/chrome/browser/ui/cocoa/js_modal_dialog_cocoa.mm
@@ -107,10 +107,10 @@ JSModalDialogCocoa::JSModalDialogCocoa(JavaScriptAppModalDialog* dialog)
   bool text_field = false;
   bool one_button = false;
   switch (dialog_->dialog_flags()) {
-    case ui::MessageBoxFlags::kIsJavascriptAlert:
+    case ui::MESSAGE_BOX_IS_JAVASCRIPT_ALERT_DIALOG:
       one_button = true;
       break;
-    case ui::MessageBoxFlags::kIsJavascriptConfirm:
+    case ui::MESSAGE_BOX_IS_JAVASCRIPT_CONFIRM_DIALOG:
       if (dialog_->is_before_unload_dialog()) {
         default_button = l10n_util::GetNSStringWithFixup(
             IDS_BEFOREUNLOAD_MESSAGEBOX_OK_BUTTON_LABEL);
@@ -118,7 +118,7 @@ JSModalDialogCocoa::JSModalDialogCocoa(JavaScriptAppModalDialog* dialog)
             IDS_BEFOREUNLOAD_MESSAGEBOX_CANCEL_BUTTON_LABEL);
       }
       break;
-    case ui::MessageBoxFlags::kIsJavascriptPrompt:
+    case ui::MESSAGE_BOX_IS_JAVASCRIPT_PROMPT_DIALOG:
       text_field = true;
       break;