Media Grid: remove Router code that doesn't actually ever run.

See #29121.

Built from https://develop.svn.wordpress.org/trunk@29444


git-svn-id: http://core.svn.wordpress.org/trunk@29222 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/js/media-grid.js

@@ -487,11 +487,7 @@
 		 */
 		keyEvent: function( event ) {
 			var $target = $( event.target );
-			// Pressing the escape key routes back to main url
-			if ( event.keyCode === 27 ) {
-				this.resetRoute();
-				return event;
-			}
+
 			//Don't go left/right if we are in a textarea or input field
 			if ( $target.is( 'input' ) || $target.is( 'textarea' ) ) {
 				return event;