Componentize component_updater: Move some paths/constants to component.

components/component_updater/common/pref_names.h

Index: components/component_updater/common/pref_names.h
diff --git a/components/component_updater/common/pref_names.h b/components/component_updater/common/pref_names.h
new file mode 100644
index 0000000000000000000000000000000000000000..1feb38670e34d4f27ea71fafd97e06758d8012a0
--- /dev/null
+++ b/components/component_updater/common/pref_names.h
@@ -0,0 +1,14 @@
+// Copyright 2014 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 COMPONENTS_COMPONENT_UPDATER_COMMON_PREF_NAMES_H_
+#define COMPONENTS_COMPONENT_UPDATER_COMMON_PREF_NAMES_H_
+
+namespace prefs {
+
+extern const char kRecoveryComponentVersion[];
+
+}  // namespace prefs
+
+#endif  // COMPONENTS_COMPONENT_UPDATER_COMMON_PREF_NAMES_H_