* Electron version: 1.7.2
* Operating system: macOS 10.12.5

### Expected behavior

Forked processes can be started with `--inspect` or `--inspect-brk` for debugging them.

### Actual behavior

This option does not seem to have any impact.

### How to reproduce

* `git clone https://github.com/bpasero/electron-inspect.git`
* `npm install`
* `./node_modules/.bin/electron .`

=> we fork the process in https://github.com/bpasero/electron-inspect/blob/master/fork.js#L3
=> you see a file `tempXYZ` appearing which means `script.js` was executed
=> this is unexpected because `fork.js` was forked with `--inspect-brk`

atom/app/node_main.cc
#include "atom/app/node_main.h"
#include "atom/app/uv_task_runner.h"
#include "atom/browser/javascript_environment.h"
#include "atom/common/api/atom_bindings.h"
#include "atom/common/crash_reporter/crash_reporter.h"
#include "atom/common/native_mate_converters/string16_converter.h"
#include "base/command_line.h"
#include "base/feature_list.h"
#include "base/threading/thread_task_runner_handle.h"
#include "gin/array_buffer.h"
#include "gin/public/isolate_holder.h"
#include "gin/v8_initializer.h"
#include "native_mate/dictionary.h"
#include "atom/common/node_includes.h"
namespace atom {
int NodeMain(int argc, char *argv[]) {