- Electron version: 1.2.2, and 1.3.1 (I only tested the 2 versions)
- Operating system: Windows 10

steps:

1.　Register a  custom protocol **`"app"`** by `protocol.registerFileProtocol`

```
    protocol.registerStandardSchemes(['app']);
    app.on('ready', function(){
        protocol.registerFileProtocol('app', (request, callback) => {
            //.......
        });
        //.......
    });
```

2.　call `cookies.set` for **`app://myhost/`**

```
    session.defaultSession.cookies.set({
            url : 'app://myhost/',      //custom protocol
            name : 'test',
            value : '12345'
        },
        (error)=>{
            if(error){
                console.log(error);  //error occurred here
            }
        }
    );
```

With url of custom protocol, an error will occur.  

If using standard http protocol, the code works well.

```
    session.defaultSession.cookies.set({
            url : 'http://otherhost/',     //standard http protocol
            name : 'test',
            value : '12345'
        },
        (error)=>{  //works well, no error
            if(error){
                console.log(error);
            }
        }
    );
```

atom/browser/atom_browser_context.cc
#include "atom/browser/atom_browser_context.h"
#include "atom/browser/atom_browser_main_parts.h"
#include "atom/browser/atom_download_manager_delegate.h"
#include "atom/browser/browser.h"
#include "atom/browser/net/atom_cert_verifier.h"
#include "atom/browser/net/atom_network_delegate.h"
#include "atom/browser/net/atom_ssl_config_service.h"
#include "atom/browser/net/atom_url_request_job_factory.h"
#include "atom/browser/net/asar/asar_protocol_handler.h"
#include "atom/browser/net/http_protocol_handler.h"
#include "atom/browser/atom_permission_manager.h"
#include "atom/browser/web_view_manager.h"
#include "atom/common/atom_version.h"
#include "atom/common/chrome_version.h"
#include "atom/common/options_switches.h"
#include "base/command_line.h"
#include "base/files/file_path.h"
#include "base/memory/ptr_util.h"
#include "base/path_service.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/threading/sequenced_worker_pool.h"
#include "base/threading/worker_pool.h"
#include "chrome/common/chrome_paths.h"