### Issue Details
in frameless windows 
While setting browserview style to draggable by webkit-app-region : drag. the area won't be draggable after that
and it can not move main window 
### Electron Version:
11.0.1
### Operating System:
Windows 10 (1803)
Last Known Working Electron version:
not found
### Expected Behavior
Browser view moves the main window while I set the style of the body or one of the area to
-webkit-app-region: drag;

### Actual Behavior
nothing happen in browserview after styling -webkit-app-region: drag;

I know it is mention that in 11 version it is fixed. but it still dosn't work 

### To Reproduce
https://gist.github.com/pejmanpesyan/8540aad65e7c6980c45f23e5eaafafb9

shell/browser/native_window_views.cc
#include "shell/browser/native_window_views.h"
#if defined(OS_WIN)
#include <wrl/client.h>
#endif
#include <memory>
#include <tuple>
#include <utility>
#include <vector>
#include "base/numerics/ranges.h"
#include "base/stl_util.h"
#include "base/strings/utf_string_conversions.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/desktop_media_id.h"
#include "shell/browser/api/electron_api_web_contents.h"
#include "shell/browser/native_browser_view_views.h"
#include "shell/browser/ui/drag_util.h"
#include "shell/browser/ui/inspectable_web_contents.h"
#include "shell/browser/ui/inspectable_web_contents_view.h"
#include "shell/browser/ui/views/root_view.h"
#include "shell/browser/web_contents_preferences.h"
#include "shell/browser/web_view_manager.h"
#include "shell/browser/window_list.h"
#include "shell/common/electron_constants.h"
#include "shell/common/gin_converters/image_converter.h"
#include "shell/common/gin_helper/dictionary.h"
#include "shell/common/options_switches.h"
#include "ui/aura/window_tree_host.h"
#include "ui/base/hit_test.h"
#include "ui/gfx/image/image.h"