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* Electron version: 1.6.1
* Operating system: macOS

### Expected behavior

navigator.geolocation.getCurrentPosition runs in background

### Actual behavior

the entire UI is frozen

### How to reproduce

```js
    navigator.geolocation.getCurrentPosition((pos) => {
      console.log('POS: ' + pos);
    }, (err) => {
      console.log('Geolocation error: ', err);
    }, {enableHighAccuracy: false});
```
atom/browser/api/atom_api_web_contents.cc
if (IsDevToolsOpened())
    CloseDevTools();
  else
    OpenDevTools(nullptr);
}
void WebContents::InspectElement(int x, int y) {
  if (type_ == REMOTE)
    return;
  if (!enable_devtools_)
    return;
  if (!managed_web_contents()->GetDevToolsWebContents())
    OpenDevTools(nullptr);
  managed_web_contents()->InspectElement(x, y);
}
void WebContents::InspectServiceWorker() {
  if (type_ == REMOTE)
    return;
  if (!enable_devtools_)
    return;
  for (const auto& agent_host : content::DevToolsAgentHost::GetOrCreateAll()) {
    if (agent_host->GetType() ==
        content::DevToolsAgentHost::kTypeServiceWorker) {
      OpenDevTools(nullptr);
      managed_web_contents()->AttachTo(agent_host);
      break;
    }
  }
}
void WebContents::HasServiceWorker(