Implement FeatureProvider for ExtensionAPI.

chrome/common/extensions/feature_provider.h

Index: chrome/common/extensions/feature_provider.h
diff --git a/chrome/common/extensions/feature_provider.h b/chrome/common/extensions/feature_provider.h
new file mode 100644
index 0000000000000000000000000000000000000000..0db046834749f952022314ee1246d9e01ab3cd62
--- /dev/null
+++ b/chrome/common/extensions/feature_provider.h
@@ -0,0 +1,29 @@
+// 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_FEATURE_PROVIDER_H_
+#define CHROME_COMMON_EXTENSIONS_FEATURE_PROVIDER_H_
+#pragma once
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+
+namespace extensions {
+
+class Feature;
+
+// Implemented by classes that can vend features.
+class FeatureProvider {
+ public:
+  FeatureProvider() {}
+  virtual ~FeatureProvider() {}
+
+  // Returns the feature with the specified name.
+  virtual scoped_ptr<Feature> GetFeature(const std::string& name) = 0;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_COMMON_EXTENSIONS_FEATURE_PROVIDER_H_