* 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
window_->SetAutoHideMenuBar(auto_hide);
}
bool BrowserWindow::IsMenuBarAutoHide() {
  return window_->IsMenuBarAutoHide();
}
void BrowserWindow::SetMenuBarVisibility(bool visible) {
  window_->SetMenuBarVisibility(visible);
}
bool BrowserWindow::IsMenuBarVisible() {
  return window_->IsMenuBarVisible();
}
#if defined(OS_WIN)
bool BrowserWindow::HookWindowMessage(UINT message,
                               const MessageCallback& callback) {
  messages_callback_map_[message] = callback;
  return true;
}
void BrowserWindow::UnhookWindowMessage(UINT message) {
  if (!ContainsKey(messages_callback_map_, message))
    return;
  messages_callback_map_.erase(message);
}
bool BrowserWindow::IsWindowMessageHooked(UINT message) {
  return ContainsKey(messages_callback_map_, message);
}
void BrowserWindow::UnhookAllWindowMessages() {
  messages_callback_map_.clear();
}
bool BrowserWindow::SetThumbnailClip(const gfx::Rect& region) {