Convert server to use RangeFactory

pkg/analyzer_plugin/test/utilities/range_factory_test.dart

Index: pkg/analyzer_plugin/test/utilities/range_factory_test.dart
diff --git a/pkg/analyzer_plugin/test/utilities/range_factory_test.dart b/pkg/analyzer_plugin/test/utilities/range_factory_test.dart
index df120d832238e15bd01c2595d19a1b90c46b855c..9a166f521b06b1724219ccd6b7dfe17b506b4f6b 100644
--- a/pkg/analyzer_plugin/test/utilities/range_factory_test.dart
+++ b/pkg/analyzer_plugin/test/utilities/range_factory_test.dart
@@ -76,6 +76,14 @@ class SourceRangesTest extends AbstractSingleUnitTest {
     expect(range.nodes([]), new SourceRange(0, 0));
   }
 
+  test_offsetBy() {
+    expect(range.offsetBy(new SourceRange(7, 3), 2), new SourceRange(9, 3));
+  }
+
+  test_offsetEndIndex() {
+    expect(range.offsetEndIndex(6, 11), new SourceRange(6, 5));
+  }
+
   test_startEnd_nodeNode() async {
     await resolveTestUnit(' main() {}');
     FunctionDeclaration mainFunction = testUnit.declarations[0];