### 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 "ui/gfx/native_widget_types.h"
#include "ui/views/background.h"
#include "ui/views/controls/webview/unhandled_keyboard_event_handler.h"
#include "ui/views/controls/webview/webview.h"
#include "ui/views/widget/native_widget_private.h"
#include "ui/views/widget/widget.h"
#include "ui/views/window/client_view.h"
#include "ui/wm/core/shadow_types.h"
#include "ui/wm/core/window_util.h"
#if defined(OS_LINUX)
#include "base/strings/string_util.h"
#include "shell/browser/browser.h"
#include "shell/browser/linux/unity_service.h"
#include "shell/browser/ui/views/frameless_view.h"
#include "shell/browser/ui/views/native_frame_view.h"
#include "ui/views/widget/desktop_aura/desktop_window_tree_host_linux.h"
#include "ui/views/window/native_frame_view.h"
#if defined(USE_X11)
#include "shell/browser/ui/views/global_menu_bar_x11.h"
#include "shell/browser/ui/x/event_disabler.h"
#include "shell/browser/ui/x/window_state_watcher.h"
#include "shell/browser/ui/x/x_window_utils.h"
#include "ui/base/x/x11_util.h"
#include "ui/gfx/x/shape.h"
#include "ui/gfx/x/x11_atom_cache.h"
#include "ui/gfx/x/xproto.h"
#endif
#if defined(USE_OZONE) || defined(USE_X11)
#include "ui/base/ui_base_features.h"
#endif