Add an integration test for kythe support with bug fixes

pkg/analyzer_plugin/test/plugin/kythe_mixin_test.dart

Index: pkg/analyzer_plugin/test/plugin/kythe_mixin_test.dart
diff --git a/pkg/analyzer_plugin/test/plugin/kythe_mixin_test.dart b/pkg/analyzer_plugin/test/plugin/kythe_mixin_test.dart
index dce02716712147227643331407b16bd94ca14c1d..a3af8830740d6c53da60a48cb2f8451cf87bd2d5 100644
--- a/pkg/analyzer_plugin/test/plugin/kythe_mixin_test.dart
+++ b/pkg/analyzer_plugin/test/plugin/kythe_mixin_test.dart
@@ -83,11 +83,11 @@ class _TestServerPlugin extends MockServerPlugin with EntryMixin {
     KytheVName vName = new KytheVName('', '', '', '', '');
     return <EntryContributor>[
       new _TestEntryContributor(<KytheEntry>[
-        new KytheEntry(vName, '', vName, '', <int>[]),
-        new KytheEntry(vName, '', vName, '', <int>[])
+        new KytheEntry(vName, '', target: vName),
+        new KytheEntry(vName, '', target: vName)
       ]),
       new _TestEntryContributor(
-          <KytheEntry>[new KytheEntry(vName, '', vName, '', <int>[])])
+          <KytheEntry>[new KytheEntry(vName, '', target: vName)])
     ];
   }