Add the --disable-off-store-extension-install switch.

chrome/common/extensions/switch_utils.h

Index: chrome/common/extensions/switch_utils.h
diff --git a/chrome/common/extensions/switch_utils.h b/chrome/common/extensions/switch_utils.h
new file mode 100644
index 0000000000000000000000000000000000000000..47eab6245e2ffcba40bd80b186fcce2b7ebb6eee
--- /dev/null
+++ b/chrome/common/extensions/switch_utils.h
@@ -0,0 +1,19 @@
+// 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_COMMON_EXTENSIONS_SWITCH_UTILS_H_
+#define CHROME_COMMON_EXTENSIONS_SWITCH_UTILS_H_
+#pragma once
+
+namespace extensions {
+
+namespace switch_utils {
+
+bool IsOffStoreInstallEnabled();
+
+}  // switch_utils
+
+}  // extensions
+
+#endif  // CHROME_COMMON_EXTENSIONS_SWITCH_UTILS_H_