Bug 498976 - Scroll the selected tab into view on mouseover when it's only partially visible. r=dao

--HG--
extra : rebase_source : 8ad50aca55a0ec462c079a7fa2c48e826eb369b3

browser/base/content/tabbrowser.xml

@@ -7038,6 +7038,10 @@
           let tabContainer = this.parentNode;
           let visibleTabs = tabContainer.tabbrowser.visibleTabs;
           let tabIndex = visibleTabs.indexOf(this);
+
+          if (this.selected)
+            tabContainer._handleTabSelect();
+
           if (tabIndex == 0) {
             tabContainer._beforeHoveredTab = null;
           } else {