- Electron version: v1.2.2
- Operating system: OS X El Capitan 10.11.5

When `<webview>.isAudioMuted() === true` [Notifications](https://developer.mozilla.org/de/docs/Web/API/notification) from the Webview still make sounds.

atom/browser/atom_browser_client.cc
return new AtomAccessTokenStore;
}
void AtomBrowserClient::OverrideWebkitPrefs(
    content::RenderViewHost* host, content::WebPreferences* prefs) {
  prefs->javascript_enabled = true;
  prefs->web_security_enabled = true;
  prefs->javascript_can_open_windows_automatically = true;
  prefs->plugins_enabled = true;
  prefs->dom_paste_enabled = true;
  prefs->allow_scripts_to_close_windows = true;
  prefs->javascript_can_access_clipboard = true;
  prefs->local_storage_enabled = true;
  prefs->databases_enabled = true;
  prefs->application_cache_enabled = true;
  prefs->allow_universal_access_from_file_urls = true;
  prefs->allow_file_access_from_file_urls = true;
  prefs->experimental_webgl_enabled = true;
  prefs->allow_displaying_insecure_content = false;
  prefs->allow_running_insecure_content = false;
  
  auto web_contents = content::WebContents::FromRenderViewHost(host);
  WebContentsPreferences::OverrideWebkitPrefs(web_contents, prefs);
}
std::string AtomBrowserClient::GetApplicationLocale() {
  return l10n_util::GetApplicationLocale("");
}
void AtomBrowserClient::OverrideSiteInstanceForNavigation(