Enforce the 'requirements' field in manifests.

chrome/common/extensions/requirements_provider.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_COMMON_EXTENSIONS_REQUIREMENTS_PROVIDER_H_
+#define CHROME_COMMON_EXTENSIONS_REQUIREMENTS_PROVIDER_H_
+#pragma once
+
+#include "base/string16.h"
+
+namespace extensions {
+class Manifest;
+
+class RequirementsProvider {

[Aaron Boodman, 2012/07/16 21:16:12]

I don't think this needs to be abstract for now. The implementation is all going
to be in c/b/e. Just create a concrete RequirementsProvider in c/b/e?

+ public:
+  static RequirementsProvider* Create();
+
+  virtual ~RequirementsProvider() {}
+
+  virtual bool Supports(const Manifest& manifest, string16* error) = 0;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_COMMON_EXTENSIONS_REQUIREMENTS_PROVIDER_H_