Force COM machinery to notice that the path to the DelegateExecute verb handler has changed.

chrome/installer/util/callback_work_item.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_INSTALLER_UTIL_CALLBACK_WORK_ITEM_H_
+#define CHROME_INSTALLER_UTIL_CALLBACK_WORK_ITEM_H_
+
+#include "base/callback.h"
+#include "base/compiler_specific.h"
+#include "base/gtest_prod_util.h"
+#include "chrome/installer/util/work_item.h"
+
+// A work item that invokes a callback on Do() and Rollback().  In the following
+// example, the function SomeWorkItemCallback() will be invoked when an item
+// list is processed.
+//
+// // A callback invoked to do some work.
+// bool SomeWorkItemCallback(const CallbackWorkItem& item) {
+//   if (item.IsRollback()) {
+//     // Rollback work goes here.  The return value is ignored in this case.
+//     return true;
+//   }
+//
+//   // Roll forward work goes here.  The return value indicates success/failure
+//   // of the item.
+//   return true;
+// }
+//
+// void SomeFunctionThatAddsItemsToAList(WorkItemList* item_list) {
+//   ...
+//   item_list->AddCallbackWorkItem(base::Bind(&SomeWorkItemCallback));
+//   ...
+// }
+class CallbackWorkItem : public WorkItem {
+ public:
+  virtual ~CallbackWorkItem();
+
+  virtual bool Do() OVERRIDE;
+  virtual void Rollback() OVERRIDE;
+
+  bool IsRollback() const;
+
+ private:
+  friend class WorkItem;
+
+  enum RollState {
+    RS_UNDEFINED,
+    RS_FORWARD,
+    RS_BACKWARD,
+  };
+
+  CallbackWorkItem(base::Callback<bool(const CallbackWorkItem&)> callback);
+
+  base::Callback<bool(const CallbackWorkItem&)> callback_;
+  RollState roll_state_;
+
+  FRIEND_TEST_ALL_PREFIXES(CallbackWorkItemTest, TestFailure);
+  FRIEND_TEST_ALL_PREFIXES(CallbackWorkItemTest, TestForwardBackward);
+};
+
+#endif  // CHROME_INSTALLER_UTIL_CALLBACK_WORK_ITEM_H_