Implement ComplexFeature to support permission features with multiple rules.

chrome/common/extensions/features/simple_feature_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_FEATURES_SIMPLE_FEATURE_PROVIDER_H_
 #define CHROME_COMMON_EXTENSIONS_FEATURES_SIMPLE_FEATURE_PROVIDER_H_
 
+#include <map>
 #include <set>
 #include <string>
 
 #include "base/memory/linked_ptr.h"
 #include "base/values.h"
 #include "chrome/common/extensions/features/feature.h"
 #include "chrome/common/extensions/features/feature_provider.h"
+#include "chrome/common/extensions/features/simple_feature.h"
 
 namespace extensions {
 
 // Reads Features out of a simple JSON file description.
 class SimpleFeatureProvider : public FeatureProvider {
  public:
-  typedef Feature*(*FeatureFactory)();
+  typedef SimpleFeature*(*FeatureFactory)();
 
   // Creates a new SimpleFeatureProvider. Pass null to |factory| to have the
   // provider create plain old Feature instances.
   SimpleFeatureProvider(DictionaryValue* root, FeatureFactory factory);
   virtual ~SimpleFeatureProvider();
 
   // Gets an instance for the _manifest_features.json file that is baked into
   // Chrome as a resource.
   static SimpleFeatureProvider* GetManifestFeatures();
 
   // Gets an instance for the _permission_features.json file that is baked into
   // Chrome as a resource.
   static SimpleFeatureProvider* GetPermissionFeatures();
 
   // Returns all features described by this instance.
   std::set<std::string> GetAllFeatureNames() const;
 
   // Gets the feature |feature_name|, if it exists.
-  virtual Feature* GetFeature(const std::string& feature_name) OVERRIDE;
+  virtual SimpleFeature* GetFeature(const std::string& feature_name) OVERRIDE;
 
  private:
-  typedef std::map<std::string, linked_ptr<Feature> > FeatureMap;
+  typedef std::map<std::string, linked_ptr<SimpleFeature> > FeatureMap;
   FeatureMap features_;
 
   FeatureFactory factory_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_FEATURES_SIMPLE_FEATURE_PROVIDER_H_