When viewing a PDF, clicking the "download" button has no effect. It should trigger a download (including the `"will-download"` event and associated machinery).
shell/browser/extensions/electron_extensions_api_client.cc
const content::ContextMenuParams& params) override {
    
    LOG(INFO) << "HCM";
    return true;
  }
  void RecordLoadMetric(bool in_main_frame,
                        const std::string& mime_type) override {}
 private:
  DISALLOW_COPY_AND_ASSIGN(ElectronMimeHandlerViewGuestDelegate);
};
ElectronExtensionsAPIClient::ElectronExtensionsAPIClient() = default;
ElectronExtensionsAPIClient::~ElectronExtensionsAPIClient() = default;
MessagingDelegate* ElectronExtensionsAPIClient::GetMessagingDelegate() {
  if (!messaging_delegate_)
    messaging_delegate_ = std::make_unique<ElectronMessagingDelegate>();
  return messaging_delegate_.get();
}
void ElectronExtensionsAPIClient::AttachWebContentsHelpers(
    content::WebContents* web_contents) const {
  extensions::ElectronExtensionWebContentsObserver::CreateForWebContents(
      web_contents);
}
std::unique_ptr<MimeHandlerViewGuestDelegate>
ElectronExtensionsAPIClient::CreateMimeHandlerViewGuestDelegate(
    MimeHandlerViewGuest* guest) const {
  return std::make_unique<ElectronMimeHandlerViewGuestDelegate>();
}
}