Add policy provider that would filter extensions/apps allowed on the

chrome/browser/chromeos/extensions/signin_screen_policy_provider.h

Index: chrome/browser/chromeos/extensions/signin_screen_policy_provider.h
diff --git a/chrome/browser/chromeos/extensions/signin_screen_policy_provider.h b/chrome/browser/chromeos/extensions/signin_screen_policy_provider.h
new file mode 100644
index 0000000000000000000000000000000000000000..cb7712598491c472b8e5301c3b2fd9bc3c57ca48
--- /dev/null
+++ b/chrome/browser/chromeos/extensions/signin_screen_policy_provider.h
@@ -0,0 +1,34 @@
+// Copyright 2013 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_BROWSER_CHROMEOS_EXTENSIONS_SIGNIN_SCREEN_POLICY_PROVIDER_H_
+#define CHROME_BROWSER_CHROMEOS_EXTENSIONS_SIGNIN_SCREEN_POLICY_PROVIDER_H_
+
+#include "base/compiler_specific.h"
+#include "base/macros.h"
+#include "chrome/browser/chromeos/policy/device_local_account.h"
+#include "extensions/browser/management_policy.h"
+
+namespace chromeos {
+
+// A managed policy for apps on chromeos login screen.
+// It ensures that only very limited set of APIs are avaliable for such apps.
+class SigninScreenPolicyProvider
+    : public extensions::ManagementPolicy::Provider {
+ public:
+  SigninScreenPolicyProvider();
+  ~SigninScreenPolicyProvider() override;
+
+  // extensions::ManagementPolicy::Provider:
+  std::string GetDebugPolicyProviderName() const override;
+  bool UserMayLoad(const extensions::Extension* extension,
+                   base::string16* error) const override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(SigninScreenPolicyProvider);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_SIGNIN_SCREEN_POLICY_PROVIDER_H_