Fix for nested TabLayoutPanel visibility bug.
Review: jlabanca (desk check)

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@7077 8db76d5a-ed1c-0410-87a9-c151d255dfc7

user/src/com/google/gwt/user/client/ui/TabLayoutPanel.java

diff --git a/user/src/com/google/gwt/user/client/ui/TabLayoutPanel.java b/user/src/com/google/gwt/user/client/ui/TabLayoutPanel.java
index d358ea4..43c38f3 100644
--- a/user/src/com/google/gwt/user/client/ui/TabLayoutPanel.java
+++ b/user/src/com/google/gwt/user/client/ui/TabLayoutPanel.java
@@ -358,7 +358,7 @@
     }
 
     Element container = panel.getWidgetContainerElement(children.get(index));
-    container.getStyle().setVisibility(Visibility.VISIBLE);
+    container.getStyle().clearVisibility();
     tabs.get(index).setSelected(true);
     selectedIndex = index;