These events are emitted for every navigation request which isn't really efficient. Also upstream has removed the observers that provide these details as part of network servification https://chromium-review.googlesource.com/c/chromium/src/+/805008 and https://chromium-review.googlesource.com/c/chromium/src/+/786320. We are removing it as a part of chromium 66 upgrade.

Proposed alternative: Users can use the [webRequest](https://github.com/electron/electron/blob/master/docs/api/web-request.md) module which provides similar navigation details on a subscription basis.
atom/browser/api/atom_api_web_contents.cc
content::WebContents* source,
    const content::OpenURLParams& params) {
  if (params.disposition != WindowOpenDisposition::CURRENT_TAB) {
    if (type_ == BROWSER_WINDOW || type_ == OFF_SCREEN)
      Emit("-new-window", params.url, "", params.disposition);
    else
      Emit("new-window", params.url, "", params.disposition);
    return nullptr;
  }
  
  if (Emit("will-navigate", params.url))
    return nullptr;
  
  
  if (IsDestroyed())
    return nullptr;
  return CommonWebContentsDelegate::OpenURLFromTab(source, params);
}
void WebContents::BeforeUnloadFired(content::WebContents* tab,