Issue #766170 follow-up by tim.plunkett: Committing CSS file for Overlay RTL styling.

modules/overlay/overlay-child-rtl.css

+
+html {
+  direction: rtl;
+}
+
+#overlay-title {
+  float: right;
+  left: auto;
+}
+#overlay {
+  padding: 0.2em;
+  padding-left: 26px;
+}
+#overlay-close-wrapper {
+  left: 0;
+  right: auto;
+}
+#overlay-close,
+#overlay-close:hover {
+  background: transparent url(images/close-rtl.png) no-repeat;
+  -moz-border-radius-topright: 0;
+  -webkit-border-top-right-radius: 0;
+  border-top-right-radius: 0;
+}
+
+/**
+ * Tabs on the overlay.
+ */
+#overlay-tabs {
+  left: 20px;
+  right: auto;
+}
+#overlay-tabs li {
+  margin: 0 -3px 0 O;
+}