* Electron version: 1.6.15
* Operating system: Linux

### Expected behavior

Open a `BrowserWindow` with passed options

### Actual behavior

  - Usually a Segmentation fault.
  - Sometimes `[12843:0100/000000.043847:FATAL:zygote_linux.cc(479)] Failed to synchronise with parent zygote process`
  - Sometimes `[12819:0100/000000.719122:FATAL:zygote_linux.cc(509)] Check failed: len > 0 (0 vs. 0)`

### How to reproduce

I'm still working on making a smaller reproduction case. The issue goes away with small tweaks.

1. Starting from https://github.com/daurnimator/fengari-electron-example
2. Modify main.lua to contain:
```lua
local js = require "js"
local electron = require "electron"

electron.app:on("ready", function()
	local win = js.new(electron.BrowserWindow, js.createproxy({
		backgroundColor = '#2e2c29';
	}, "object"))
	win:loadURL("https://fengari.io")
end)
```

atom/browser/api/atom_api_window.cc
Emit("swipe", direction);
}
void Window::OnWindowSheetBegin() {
  Emit("sheet-begin");
}
void Window::OnWindowSheetEnd() {
  Emit("sheet-end");
}
void Window::OnWindowEnterHtmlFullScreen() {
  Emit("enter-html-full-screen");
}
void Window::OnWindowLeaveHtmlFullScreen() {
  Emit("leave-html-full-screen");
}
void Window::OnRendererUnresponsive() {
  Emit("unresponsive");
}
void Window::OnRendererResponsive() {
  Emit("responsive");
}
void Window::OnExecuteWindowsCommand(const std::string& command_name) {
  Emit("app-command", command_name);
}
void Window::OnTouchBarItemResult(const std::string& item_id,
                                  const base::DictionaryValue& details) {
  Emit("-touch-bar-interaction", item_id, details);
}
void Window::OnNewWindowForTab() {