Converted Observatory persistent-hangles-page element

runtime/observatory/tests/observatory_ui/mocks/objects/persistent_handles.dart

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+part of mocks;
+
+class PersistentHandlesMock implements M.PersistentHandles {
+  final Iterable<M.PersistentHandle> elements;
+  final Iterable<M.WeakPersistentHandle> weakElements;
+
+  const PersistentHandlesMock({this.elements: const [],
+                               this.weakElements: const []});
+}
+
+class PersistentHandleMock implements M.PersistentHandle {
+  final M.ObjectRef object;
+
+  const PersistentHandleMock({this.object: const InstanceRefMock()});
+}
+
+class WeakPersistentHandleMock implements M.WeakPersistentHandle {
+  final M.ObjectRef object;
+  final int externalSize;
+  final String peer;
+  final String callbackSymbolName;
+  final String callbackAddress;
+
+  const WeakPersistentHandleMock({this.object: const InstanceRefMock(),
+                                  this.externalSize: 0, this.peer: '0x0',
+                                  this.callbackSymbolName: 'dart::Something()',
+                                  this.callbackAddress: '0x123456'});
+}