Converted Observatory class-tree element

runtime/observatory/tests/observatory_ui/mocks/repositories/script.dart

Index: runtime/observatory/tests/observatory_ui/mocks/repositories/script.dart
diff --git a/runtime/observatory/tests/observatory_ui/mocks/repositories/script.dart b/runtime/observatory/tests/observatory_ui/mocks/repositories/script.dart
index 7ab91142f1aca5134fa145d4d73443b62935d40d..78b96106e8a911bc49512a43a9934b06e449346c 100644
--- a/runtime/observatory/tests/observatory_ui/mocks/repositories/script.dart
+++ b/runtime/observatory/tests/observatory_ui/mocks/repositories/script.dart
@@ -4,16 +4,18 @@
 
 part of mocks;
 
-class ScriptRepositoryMock implements M.ScriptRepository {
-  final Map<String, M.Script> scripts;
+typedef Future<M.Script> ScriptRepositoryMockCallback(String id);
 
-  bool _invoked = false;
-  bool get invoked => _invoked;
+class ScriptRepositoryMock implements M.ScriptRepository {
+  final ScriptRepositoryMockCallback _get;
 
-  ScriptRepositoryMock(this.scripts);
+  ScriptRepositoryMock({ScriptRepositoryMockCallback getter})
+    : _get = getter;
 
-  Future<M.Script> get(String id) async {
-    _invoked = true;
-    return scripts[id];
+  Future<M.Script> get(String id){
+    if (_get != null) {
+      return _get(id);
+    }
+    return new Future.value(null);
   }
 }