- Electron version: 1.2.2
- Operating system: Linux

This is a problem only in linux. It works in OSX.

``` javascript
win.hide()
win.capturePage(function(img){
 // never called
})
```

shell/browser/api/electron_api_web_contents.cc
const std::string& channel,
                          blink::CloneableMessage arguments,
                          content::RenderFrameHost* render_frame_host) {
  TRACE_EVENT1("electron", "WebContents::Message", "channel", channel);
   webContents.emit('-ipc-message', new Event(), internal, channel,
   arguments);
  EmitWithSender("-ipc-message", render_frame_host,
                 electron::mojom::ElectronBrowser::InvokeCallback(), internal,
                 channel, std::move(arguments));
}
void WebContents::Invoke(
    bool internal,
    const std::string& channel,
    blink::CloneableMessage arguments,
    electron::mojom::ElectronBrowser::InvokeCallback callback,
    content::RenderFrameHost* render_frame_host) {
  TRACE_EVENT1("electron", "WebContents::Invoke", "channel", channel);
   webContents.emit('-ipc-invoke', new Event(), internal, channel, arguments);
  EmitWithSender("-ipc-invoke", render_frame_host, std::move(callback),
                 internal, channel, std::move(arguments));
}
void WebContents::OnFirstNonEmptyLayout(
    content::RenderFrameHost* render_frame_host) {
  if (render_frame_host == ontents()->GetMainFrame()) {
    Emit("ready-to-show");
  }
}
void WebContents::ReceivePostMessage(