Merge revision 1224 changes:

- Destroy CefMenuCreator on the UI thread thread (issue #887).

git-svn-id: https://chromiumembedded.googlecode.com/svn/branches/1453@1225 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

cef3/libcef/browser/browser_host_impl.cc

@@ -1107,6 +1107,7 @@ void CefBrowserHostImpl::DestroyBrowser() {
   response_manager_.reset(NULL);
   content::WebContentsObserver::Observe(NULL);
   web_contents_.reset(NULL);
+  menu_creator_.reset(NULL);
 
   DetachAllFrames();