### Issue Details

* **Electron Version:**
  * 3.x, 4.x, 5.x, 6.x
* **Operating System:**
  * All
* **Last Known Working Electron version:**:
  * 2.x

### Expected Behavior
When navigations occur, a new process should be created for the navigation.

### Actual Behavior
When a navigation occurs _during_ a preloads scripts execution the same process is re-used as Chromium does not think the navigation has been committed yet.  This causes a memory leak and all native node modules to break.

### To Reproduce
Fiddle: https://gist.github.com/MarshallOfSound/c89aa0037c3da114d44aa3a2d1a0fc24

### Screenshots
![image](https://user-images.githubusercontent.com/6634592/55097842-eb45dd00-5079-11e9-99bf-d49c0d997bca.png)

As you can see here there are three navigation loads, the second and the third one actually have the same process ID (and are running in the same process)
shell/browser/atom_browser_client.cc
DCHECK_CURRENTLY_ON(BrowserThread::IO);
  g_io_thread_application_locale.Get() = locale;
}
#if defined(OS_WIN)
const base::FilePath::StringPieceType kPathDelimiter = FILE_PATH_LITERAL(";");
#else
const base::FilePath::StringPieceType kPathDelimiter = FILE_PATH_LITERAL(":");
#endif
}  
void AtomBrowserClient::SuppressRendererProcessRestartForOnce() {
  g_suppress_renderer_process_restart = true;
}
AtomBrowserClient* AtomBrowserClient::Get() {
  return g_browser_client;
}
void AtomBrowserClient::SetApplicationLocale(const std::string& locale) {
  if (!BrowserThread::IsThreadInitialized(BrowserThread::IO) ||
      !base::PostTaskWithTraits(
          FROM_HERE, {BrowserThread::IO},
          base::BindOnce(&SetApplicationLocaleOnIOThread, locale))) {
    g_io_thread_application_locale.Get() = locale;
  }
  *g_application_locale = locale;
}
AtomBrowserClient::AtomBrowserClient() {