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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_render_frame_observer.cc
bool send_to_all,
                                               const std::string& channel,
                                               const base::ListValue& args,
                                               int32_t sender_id) {
  
  
  
  
  
  if (!document_created_)
    return;
  blink::WebLocalFrame* frame = render_frame_->GetWebFrame();
  if (!frame || !render_frame_->IsMainFrame())
    return;
  EmitIPCEvent(frame, internal, channel, args, sender_id);
  
  if (send_to_all) {
    for (blink::WebFrame* child = frame->FirstChild(); child;
         child = child->NextSibling())
      if (child->IsWebLocalFrame()) {
        EmitIPCEvent(child->ToWebLocalFrame(), internal, channel, args,
                     sender_id);
      }
  }
}
void AtomRenderFrameObserver::OnTakeHeapSnapshot(