When deleting an image in the editor with the delete or backspace keys, hide the edit and delete popup buttons.

Props azaozz, lessbloat
fixes #22717


git-svn-id: https://develop.svn.wordpress.org/trunk@23046 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/js/tinymce/plugins/wordpress/editor_plugin_src.js

@@ -307,6 +307,11 @@
 					ed.plugins.wordpress._hideButtons();
 			});
 
+			ed.onKeyDown.add(function(ed, e){
+				if ( e.which == tinymce.VK.DELETE || e.which == tinymce.VK.BACKSPACE )
+					ed.plugins.wordpress._hideButtons();
+			});
+
 			closeOnClick = function(e){
 				var id;