Add --use-more-webui runtime flag to toggle WebUI replacements for native dialogs.

chrome/browser/ui/browser.cc

Index: chrome/browser/ui/browser.cc
diff --git a/chrome/browser/ui/browser.cc b/chrome/browser/ui/browser.cc
index 9071b40104a09d1a82ae418494b6b311b28d683c..6fa32bee4d34177ceec0b849fbef598a49a8d1bc 100644
--- a/chrome/browser/ui/browser.cc
+++ b/chrome/browser/ui/browser.cc
@@ -2882,13 +2882,12 @@ void Browser::BookmarkAllTabs() {
   BookmarkModel* model = profile()->GetBookmarkModel();
   DCHECK(model && model->IsLoaded());
 
-  BookmarkEditor::EditDetails details;
-  details.type = BookmarkEditor::EditDetails::NEW_FOLDER;
+  BookmarkEditor::EditDetails details =
+      BookmarkEditor::EditDetails::AddFolder(model->GetParentForNewNodes());
   bookmark_utils::GetURLsForOpenTabs(this, &(details.urls));
   DCHECK(!details.urls.empty());
 
-  BookmarkEditor::Show(window()->GetNativeHandle(), profile_,
-                       model->GetParentForNewNodes(),  details,
+  BookmarkEditor::Show(window()->GetNativeHandle(), profile_, details,
                        BookmarkEditor::SHOW_TREE);
 }