Fix incorrect units in TabLayoutPanel example (was PX should be
EM).

Gerrit review: http://gwt-code-reviews.appspot.com/329802/show
Issue: http://code.google.com/p/google-web-toolkit/issues/detail?id=4851

Review by: jgw@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@8039 8db76d5a-ed1c-0410-87a9-c151d255dfc7
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 00fa651..d56ec843 100644
--- a/user/src/com/google/gwt/user/client/ui/TabLayoutPanel.java
+++ b/user/src/com/google/gwt/user/client/ui/TabLayoutPanel.java
@@ -76,7 +76,7 @@
  * object, and so cannot have a <code>ui:field</code> attribute.) 
  * <p>
  * For example:<pre>
- * &lt;g:TabLayoutPanel barUnit='PX' barHeight='3'>
+ * &lt;g:TabLayoutPanel barUnit='EM' barHeight='3'>
  *  &lt;g:tab>
  *    &lt;g:header size='7'>&lt;b>HTML&lt;/b> header&lt;/g:header>
  *    &lt;g:Label>able&lt;/g:Label>