* Electron version: 1.7.9
* Operating system: macOS 10.13.1

### Expected behavior

If pinch-zoom is disabled via `webFrame.setVisualZoomLevelLimits(1, 1);` it should stay disabled.

### Actual behavior

Pinch zoom is possible. 

### How to reproduce

* connect an external monitor and open any electron app there, keep the macbook pro lid closed
* disconnect the external monitor
* open the lid

=> you can now pinch zoom 
atom/renderer/api/atom_api_web_frame.cc
blink::WebURL(GURL(url)), start_line));
  }
  bool has_user_gesture = false;
  args->GetNext(&has_user_gesture);
  blink::WebLocalFrame::ScriptExecutionType scriptExecutionType =
      blink::WebLocalFrame::kSynchronous;
  args->GetNext(&scriptExecutionType);
  ScriptExecutionCallback::CompletionCallback completion_callback;
  args->GetNext(&completion_callback);
  std::unique_ptr<blink::WebScriptExecutionCallback> callback(
      new ScriptExecutionCallback(completion_callback));
  web_frame_->RequestExecuteScriptInIsolatedWorld(
      world_id, &sources.front(), sources.size(), has_user_gesture,
      scriptExecutionType, callback.release());
}
void WebFrame::SetIsolatedWorldSecurityOrigin(
    int world_id,
    const std::string& origin_url) {
  web_frame_->SetIsolatedWorldSecurityOrigin(
      world_id,
      blink::WebSecurityOrigin::CreateFromString(
          blink::WebString::FromUTF8(origin_url)));
}
void WebFrame::SetIsolatedWorldContentSecurityPolicy(
    int world_id,
    const std::string& security_policy) {
  web_frame_->SetIsolatedWorldContentSecurityPolicy(
      world_id, blink::WebString::FromUTF8(security_policy));
}
void WebFrame::SetIsolatedWorldHumanReadableName(