- 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
base::CommandLine* command_line,
    int process_id) {
  std::string process_type = command_line->GetSwitchValueASCII("type");
  if (process_type != "renderer")
    return;
  
  static const char* const kCommonSwitchNames[] = {
    switches::kStandardSchemes,
  };
  command_line->CopySwitchesFrom(
      *base::CommandLine::ForCurrentProcess(),
      kCommonSwitchNames, arraysize(kCommonSwitchNames));
  
  if (!g_custom_service_worker_schemes.empty())
    command_line->AppendSwitchASCII(switches::kRegisterServiceWorkerSchemes,
                                    g_custom_service_worker_schemes);
#if defined(OS_WIN)
  
  PWSTR current_app_id;
  if (SUCCEEDED(GetCurrentProcessExplicitAppUserModelID(&current_app_id))) {
    command_line->AppendSwitchNative(switches::kAppUserModelId, current_app_id);
    CoTaskMemFree(current_app_id);
  }
#endif
  content::WebContents* web_contents = GetWebContentsFromProcessID(process_id);
  if (!web_contents)
    return;
  WebContentsPreferences::AppendExtraCommandLineSwitches(