CSS: Update .ui-helper-hidden-accessible to match H5BP's current .vis…

…uallyhidden. Fixes #8793 - Dialog: Internal autocomplete causes scroll bars.

(cherry picked from commit 48e0aa0)

themes/base/jquery.ui.core.css

@@ -12,7 +12,7 @@
 /* Layout helpers
 ----------------------------------*/
 .ui-helper-hidden { display: none; }
-.ui-helper-hidden-accessible { position: absolute !important; clip: rect(1px 1px 1px 1px); clip: rect(1px,1px,1px,1px); }
+.ui-helper-hidden-accessible { border: 0; clip: rect(0 0 0 0); height: 1px; margin: -1px; overflow: hidden; padding: 0; position: absolute; width: 1px; }
 .ui-helper-reset { margin: 0; padding: 0; border: 0; outline: 0; line-height: 1.3; text-decoration: none; font-size: 100%; list-style: none; }
 .ui-helper-clearfix:before, .ui-helper-clearfix:after { content: ""; display: table; }
 .ui-helper-clearfix:after { clear: both; }