- 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::WebContents* web_contents,
    net::SSLCertRequestInfo* cert_request_info,
    std::unique_ptr<content::ClientCertificateDelegate> delegate) {
  if (!cert_request_info->client_certs.empty() && delegate_) {
    delegate_->SelectClientCertificate(
        web_contents, cert_request_info, std::move(delegate));
  }
}
void AtomBrowserClient::ResourceDispatcherHostCreated() {
  resource_dispatcher_host_delegate_.reset(
      new AtomResourceDispatcherHostDelegate);
  content::ResourceDispatcherHost::Get()->SetDelegate(
      resource_dispatcher_host_delegate_.get());
}
bool AtomBrowserClient::CanCreateWindow(