TinyMCE: check if `wp.mce.views` exists before loading the wpview plugin. Fixes a js error when the rest of the media scripts are not loaded.

Fixes #36977.

git-svn-id: https://develop.svn.wordpress.org/trunk@37597 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/js/tinymce/plugins/wpview/plugin.js

@@ -5,7 +5,7 @@
 	tinymce.PluginManager.add( 'wpview', function( editor ) {
 		function noop () {}
 
-		if ( ! wp || ! wp.mce ) {
+		if ( ! wp || ! wp.mce || ! wp.mce.views ) {
 			return {
 				getView: noop
 			};