* Electron version: 1.8.2
* Operating system: macos 10.13.3

Reproducing repo: https://github.com/ibash/electron-webkit-app-drag

Demonstrates a bug where `-webkit-app-region: drag` causes a browser view in front of it to miss click events. Oddly - it does not prevent hover events.

Steps:
1. Clone https://github.com/ibash/electron-webkit-app-drag, `yarn install`, `yarn start`
2. Click "button1"
3. Click "button2"

Expected:

Clicking button1 or button2 pops up an alert: "button clicked!"

Actual:

Only clicking button2 pops up an alert: "button clicked!"

atom/browser/api/atom_api_browser_window.cc
auto window = static_cast<NativeWindowViews*>(window_.get());
  return window->taskbar_host().SetThumbnailClip(
      window_->GetAcceleratedWidget(), region);
}
bool BrowserWindow::SetThumbnailToolTip(const std::string& tooltip) {
  auto window = static_cast<NativeWindowViews*>(window_.get());
  return window->taskbar_host().SetThumbnailToolTip(
      window_->GetAcceleratedWidget(), tooltip);
}
void BrowserWindow::SetAppDetails(const mate::Dictionary& options) {
  base::string16 app_id;
  base::FilePath app_icon_path;
  int app_icon_index = 0;
  base::string16 relaunch_command;
  base::string16 relaunch_display_name;
  options.Get("appId", &app_id);
  options.Get("appIconPath", &app_icon_path);
  options.Get("appIconIndex", &app_icon_index);
  options.Get("relaunchCommand", &relaunch_command);
  options.Get("relaunchDisplayName", &relaunch_display_name);
  ui::win::SetAppDetailsForWindow(
      app_id, app_icon_path, app_icon_index,
      relaunch_command, relaunch_display_name,
      window_->GetAcceleratedWidget());
}
#endif
#if defined(TOOLKIT_VIEWS)
void BrowserWindow::SetIcon(mate::Handle<NativeImage> icon) {