Customize: Run a partial's fallback behavior (full refresh) when selective refresh fails due to a script error.

This ensures that 3rd-party scripts that users paste into Text widgets will gracefully recover and result in the expected preview.

See #27355.
Fixes #40658.


git-svn-id: https://develop.svn.wordpress.org/trunk@40771 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/js/customize-selective-refresh.js

@@ -457,6 +457,7 @@ wp.customize.selectiveRefresh = ( function( $, api ) {
 				if ( 'undefined' !== typeof console && console.error ) {
 					console.error( partial.id, error );
 				}
+				partial.fallback( error, [ placement ] );
 			}
 			/* jshint ignore:start */
 			document.write = self.orginalDocumentWrite;