* 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
int world_id,
    const std::string& name) {
  web_frame_->SetIsolatedWorldHumanReadableName(
      world_id, blink::WebString::FromUTF8(name));
}
mate::Handle<WebFrame> WebFrame::Create(v8::Isolate* isolate) {
  return mate::CreateHandle(isolate, new WebFrame(isolate));
}
blink::WebCache::ResourceTypeStats WebFrame::GetResourceUsage(
    v8::Isolate* isolate) {
  blink::WebCache::ResourceTypeStats stats;
  blink::WebCache::GetResourceTypeStats(&stats);
  return stats;
}
void WebFrame::ClearCache(v8::Isolate* isolate) {
  isolate->IdleNotificationDeadline(0.5);
  blink::WebCache::Clear();
  base::MemoryPressureListener::NotifyMemoryPressure(
    base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL);
}
v8::Local<v8::Value> WebFrame::Opener() const {
  blink::WebFrame* frame = web_frame_->Opener();
  if (frame && frame->IsWebLocalFrame())
    return mate::CreateHandle(isolate(),
                              new WebFrame(isolate(),
                                           frame->ToWebLocalFrame())).ToV8();
  else
    return v8::Null(isolate());
}
v8::Local<v8::Value> WebFrame::Parent() const {