Upon selection in a SuggestBox's pop up, focus the text field

After selecting a value from a SuggestBox's suggestion list, the
suggestion list closes and focus snaps back to the body
element. However, users expect the focus to be in the corresponding
ValueBox. So upon the user selecting a value, we set the focus to the
ValueBox per default.

Fixes issue 8051.

Change-Id: I08ba1abf8432ef4ad65c0a6b57983067d66b0d9f
Review-Link: https://gwt-review.googlesource.com/#/c/2100/

Review by: goktug@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@11593 8db76d5a-ed1c-0410-87a9-c151d255dfc7

Author: christian@quelltextlich.at

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

@@ -680,6 +680,7 @@ public void onSuggestionsReady(Request request, Response response) {
   };
   private final SuggestionCallback suggestionCallback = new SuggestionCallback() {
     public void onSuggestionSelected(Suggestion suggestion) {
+      box.setFocus(true);
       setNewSelection(suggestion);
     }
   };