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* Electron version: 1.7.2
* Operating system: macOS Sierra

### Expected behavior

Webview appear

### Actual behavior

It don't

### How to reproduce

1. Create a browser window with contextIsolation on true and webviewTag on true
2. Inside of it, add a webview
3. Run it, webview should not appear

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atom/renderer/atom_renderer_client.cc
v8::Handle<v8::Context> context,
    content::RenderFrame* render_frame) {
  if (injected_frames_.find(render_frame) == injected_frames_.end())
    return;
  injected_frames_.erase(render_frame);
  node::Environment* env = node::Environment::GetCurrent(context);
  if (environments_.find(env) == environments_.end())
    return;
  environments_.erase(env);
  mate::EmitEvent(env->isolate(), env->process_object(), "exit");
  
  if (env == node_bindings_->uv_env())
    node_bindings_->set_uv_env(nullptr);
  
  
  
  
  
  
  atom_bindings_->EnvironmentDestroyed(env);
}
bool AtomRendererClient::ShouldFork(blink::WebLocalFrame* frame,