					slug: $( this ).data( 'slug' )
				}
			};

			target.postMessage( JSON.stringify( install ), window.location.origin );
		} );

		/**
		 * Handles postMessage events.
		 *
		 * @since 4.2.0
		 * @since 4.6.0 Switched `update-plugin` action to use the queue.
		 *
		 * @param {Event} event Event interface.
		 */
		$( window ).on( 'message', function( event ) {
			var originalEvent  = event.originalEvent,
				expectedOrigin = document.location.protocol + '//' + document.location.hostname,
				message;

			if ( originalEvent.origin !== expectedOrigin ) {
				return;
			}

			message = $.parseJSON( originalEvent.data );

			if ( 'undefined' === typeof message.action ) {
				return;
			}

			switch ( message.action ) {

				// Called from `wp-admin/includes/class-wp-upgrader-skins.php`.
				case 'decrementUpdateCount':
					/** @property {string} message.upgradeType */
					wp.updates.decrementCount( message.upgradeType );
					break;

				case 'install-plugin':
				case 'update-plugin':
					/* jscs:disable requireCamelCaseOrUpperCaseIdentifiers */
					window.tb_remove();
					/* jscs:enable */

					message.data = wp.updates._addCallbacks( message.data, message.action );

					wp.updates.queue.push( message );
					wp.updates.queueChecker();
					break;
			}
		} );

		/**
		 * Adds a callback to display a warning before leaving the page.
		 *
		 * @since 4.2.0
		 */
		$( window ).on( 'beforeunload', wp.updates.beforeunload );
	} );
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