### Issue Details

* **Electron Version:**
  * 7.0.0-beta.5
* **Operating System:**
  * Windows
* **Last Known Working Electron version:**
  * 6

### Expected Behavior
```js
const filter = {
  domain: 'facebook.com'
}
const cookies = await webContents.session.cookies.get(filter) // will resolve with actual cookies
```

### Actual Behavior
```js
const filter = {
  domain: 'facebook.com',
  // url: 'https://facebook.com' - NOTE: filtering by url is working
}
const cookies = await webContents.session.cookies.get(filter) // is returning empty array
```

### To Reproduce
```js
const filter = {
  domain: 'facebook.com'
}
const cookies = await webContents.session.cookies.get(filter)
```

Filter by `domain` is returning empty array, but if I try to filter using `url` is returning the actual cookies.

Tested on all `7` beta versions.
On `6` filtering by domain was worked.

shell/browser/api/atom_api_cookies.cc
if (net::cookie_util::DomainIsHostOnly(filter))
    filter.insert(0, ".");
  std::string sub_domain(domain);
  
  if (!net::cookie_util::DomainIsHostOnly(sub_domain))
    sub_domain = sub_domain.substr(1);
  
  for (sub_domain.insert(0, "."); sub_domain.length() >= filter.length();) {
    if (sub_domain == filter)
      return true;
    const size_t next_dot = sub_domain.find('.', 1);  
    sub_domain.erase(0, next_dot);
  }
  return false;
}
bool MatchesCookie(const base::Value& filter,