Added CopyRegKeyWorkItem in support of IE low rights policy fixes.

chrome/installer/util/registry_key_backup.h

Index: chrome/installer/util/registry_key_backup.h
diff --git a/chrome/installer/util/registry_key_backup.h b/chrome/installer/util/registry_key_backup.h
new file mode 100644
index 0000000000000000000000000000000000000000..41221bd285eeb60cb1c88669232d54f7ea8241e8
--- /dev/null
+++ b/chrome/installer/util/registry_key_backup.h
@@ -0,0 +1,57 @@
+// Copyright (c) 2011 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_REGISTRY_KEY_BACKUP_H_
+#define CHROME_INSTALLER_UTIL_REGISTRY_KEY_BACKUP_H_
+#pragma once
+
+#include <windows.h>
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+
+namespace base {
+namespace win {
+class RegKey;
+}  // namespace win
+}  // namespace base
+
+// A container for a registry key, its values, and its subkeys.  We don't use
+// more obvious methods for various reasons:
+// - RegCopyTree isn't supported pre-Vista, so we'd have to do something
+//   different for XP anyway.
+// - SHCopyKey can't copy subkeys into a volatile destination, so we'd have to
+//   worry about polluting the registry.
+// We don't persist security attributes since we only delete keys that we own,
+// and we don't set custom attributes on them anyway.
+class RegistryKeyBackup {
+ public:
+  RegistryKeyBackup();
+  ~RegistryKeyBackup();
+
+  // Recursively reads |key_path| into this instance.  Backing up a non-existent
+  // key is valid.  Returns true if the backup was successful; false otherwise,
+  // in which case the state of this instance is not modified.
+  bool Initialize(HKEY root, const wchar_t* key_path);
+
+  // Writes the contents of this instance into |key|.  The contents of
+  // |key_path| are not modified If this instance is uninitialized or was
+  // initialized from a non-existent key.
+  bool WriteTo(HKEY root, const wchar_t* key_path) const;
+
+  void swap(RegistryKeyBackup& other) {
+    key_data_.swap(other.key_data_);
+  }
+
+ private:
+  class KeyData;
+
+  scoped_ptr<KeyData> key_data_;
+
+  DISALLOW_COPY_AND_ASSIGN(RegistryKeyBackup);
+};
+
+#endif  // CHROME_INSTALLER_UTIL_REGISTRY_KEY_BACKUP_H_