* 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
base::CommandLine::Init(argc, argv);
  int exit_code = 1;
  {
    
    argv = uv_setup_args(argc, argv);
    uv_loop_t* loop = uv_default_loop();
    scoped_refptr<UvTaskRunner> uv_task_runner(new UvTaskRunner(loop));
    base::ThreadTaskRunnerHandle handle(uv_task_runner);
    
    std::unique_ptr<base::FeatureList> feature_list(new base::FeatureList);
    feature_list->InitializeFromCommandLine("", "");
    base::FeatureList::SetInstance(std::move(feature_list));
    gin::V8Initializer::LoadV8Snapshot();
    gin::V8Initializer::LoadV8Natives();
    JavascriptEnvironment gin_env;
    int exec_argc;
    const char** exec_argv;
    node::Init(&argc, const_cast<const char**>(argv), &exec_argc, &exec_argv);
    node::IsolateData isolate_data(gin_env.isolate(), loop);
    node::Environment* env = node::CreateEnvironment(
        &isolate_data, gin_env.context(), argc, argv,
        exec_argc, exec_argv);
    mate::Dictionary process(gin_env.isolate(), env->process_object());