Add a missing comparator that prevents a test from working using JDK7.

Review by: johnlenz@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10883 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/dev/core/test/com/google/gwt/core/linker/ScriptChunkingTest.java b/dev/core/test/com/google/gwt/core/linker/ScriptChunkingTest.java
index f5e0e6b..eae9e8c 100644
--- a/dev/core/test/com/google/gwt/core/linker/ScriptChunkingTest.java
+++ b/dev/core/test/com/google/gwt/core/linker/ScriptChunkingTest.java
@@ -28,6 +28,7 @@
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Comparator;
 import java.util.SortedSet;
 import java.util.TreeSet;
 
@@ -79,7 +80,7 @@
 
         @Override
         public String getPropertyProvider(TreeLogger logger,
-            SortedSet<ConfigurationProperty> configProperties) throws UnableToCompleteException {
+            SortedSet<ConfigurationProperty> configProperties) {
           return null;
         }
 
@@ -93,7 +94,17 @@
           return "false";
         }
       };
-      return new TreeSet<SelectionProperty>(Arrays.asList(mockSourceMapProperty));
+
+      Comparator<SelectionProperty> comparator = new Comparator<SelectionProperty>() {
+        @Override
+        public int compare(SelectionProperty first, SelectionProperty second) {
+          return first.getName().compareTo(second.getName());
+        }
+      };
+      
+      TreeSet<SelectionProperty> result = new TreeSet<SelectionProperty>(comparator);
+      result.add(mockSourceMapProperty);
+      return result;
     }
 
     @Override