- 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.h
void OverrideSiteInstanceForNavigation(
      content::BrowserContext* browser_context,
      content::SiteInstance* current_instance,
      const GURL& dest_url,
      content::SiteInstance** new_instance) override;
  void AppendExtraCommandLineSwitches(base::CommandLine* command_line,
                                      int child_process_id) override;
  void DidCreatePpapiPlugin(content::BrowserPpapiHost* browser_host) override;
  content::QuotaPermissionContext* CreateQuotaPermissionContext() override;
  void AllowCertificateError(
      content::WebContents* web_contents,
      int cert_error,
      const net::SSLInfo& ssl_info,
      const GURL& request_url,
      content::ResourceType resource_type,
      bool overridable,
      bool strict_enforcement,
      bool expired_previous_decision,
      const base::Callback<void(bool)>& callback,
      content::CertificateRequestResultType* request) override;
  void SelectClientCertificate(
      content::WebContents* web_contents,
      net::SSLCertRequestInfo* cert_request_info,
      std::unique_ptr<content::ClientCertificateDelegate> delegate) override;
  void ResourceDispatcherHostCreated() override;
  bool CanCreateWindow(const GURL& opener_url,
                       const GURL& opener_top_level_frame_url,
                       const GURL& source_origin,
                       WindowContainerType container_type,
                       const std::string& frame_name,