Update to Chromium revision 40af916d (#303546).

- Standardize usage of virtual/override specifiers in CEF internals (see http://crbug.com/417463).

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@1903 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

libcef/browser/url_request_context_proxy.h

@@ -21,7 +21,7 @@ class URLRequestContextGetter;
 class CefURLRequestContextProxy : public net::URLRequestContext {
  public:
   explicit CefURLRequestContextProxy(net::URLRequestContextGetter* parent);
-  virtual ~CefURLRequestContextProxy();
+  ~CefURLRequestContextProxy() override;
 
   void Initialize(CefRefPtr<CefRequestContextHandler> handler);