- Electron version:
  1.3.3
- Operating system:
  OSX El Capitan

``` javascript
      function cbError(e) {
         console.error('failure', e);
      }

      navigator.webkitPersistentStorage.requestQuota( 10 * 1024* 1024, function(granted) {
        webkitRequestFileSystem(PERSISTENT, granted, cb, cbError);
      },
      cbError)
```

webkitRequestFileSystem is failing with:

```
FileError {code: 2, name: "SecurityError", message: "It was determined that certain files are unsafe fo… too many calls are being made on file resources."}code: 2message: "It was determined that certain files are unsafe for access within a Web application, or that too many calls are being made on file resources."name: "SecurityError"__proto__: FileError
```

This page is being served from a custom:// scheme if that matters.

atom/browser/atom_browser_client.cc
content::BrowserContext* browser_context,
    content::SiteInstance* current_instance,
    const GURL& url,
    content::SiteInstance** new_instance) {
  if (g_suppress_renderer_process_restart) {
    g_suppress_renderer_process_restart = false;
    return;
  }
  
  if (url.SchemeIs(url::kJavaScriptScheme))
    return;
  scoped_refptr<content::SiteInstance> site_instance =
      content::SiteInstance::CreateForURL(browser_context, url);
  *new_instance = site_instance.get();
  
  
  
  content::BrowserThread::PostTask(
      content::BrowserThread::UI, FROM_HERE,
      base::Bind(&Noop, base::RetainedRef(site_instance)));
  
  auto current_process = current_instance->GetProcess();
  auto pending_process = (*new_instance)->GetProcess();
  pending_processes_[pending_process->GetID()] = current_process->GetID();
  
  current_process->AddObserver(this);
}
void AtomBrowserClient::AppendExtraCommandLineSwitches(