
[Crash Dump.txt](https://github.com/electron/electron/files/1361356/Crash.Dump.txt)
* Electron version: 1.7.8, 1.7.5
* Operating system: macOS, Windows 10

### Expected behavior

The app should zoom in or zoom out like how it does when the dev tools is not open.

### Actual behavior

Electron Crashes and quits

### How to reproduce

1. Setup a sample Electron App
2. Make sure Zoom options and Toggle Dev Tools options are available
3. Start the app
4. Open Dev Tools using the menu or the keyboard shortcut
5. Zoom In or Zoom Out
6. Observe the crash that happens
atom/browser/api/atom_api_web_contents.cc
AtomViewHostMsg_GetZoomLevel::WriteReplyParams(reply_msg, GetZoomLevel());
  Send(reply_msg);
}
v8::Local<v8::Value> WebContents::GetWebPreferences(v8::Isolate* isolate) {
  WebContentsPreferences* web_preferences =
      WebContentsPreferences::FromWebContents(web_contents());
  return mate::ConvertToV8(isolate, *web_preferences->web_preferences());
}
v8::Local<v8::Value> WebContents::GetOwnerBrowserWindow() {
  if (owner_window())
    return Window::From(isolate(), owner_window());
  else
    return v8::Null(isolate());
}
int32_t WebContents::ID() const {
  return weak_map_id();
}
v8::Local<v8::Value> WebContents::Session(v8::Isolate* isolate) {
  return v8::Local<v8::Value>::New(isolate, session_);
}
content::WebContents* WebContents::HostWebContents() {
  if (!embedder_)
    return nullptr;
  return embedder_->web_contents();
}
void WebContents::SetEmbedder(const WebContents* embedder) {