Implement ComplexFeature to support permission features with multiple rules.

chrome/common/extensions/features/complex_feature.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_COMPLEX_FEATURE_H_
+#define CHROME_COMMON_EXTENSIONS_FEATURES_COMPLEX_FEATURE_H_
+
+#include <string>
+
+#include "base/memory/scoped_vector.h"
+#include "chrome/common/extensions/extension.h"
+#include "chrome/common/extensions/features/feature.h"
+
+namespace extensions {
+
+class SimpleFeature;
+
+// A ComplexFeature is composed of one or many SimpleFeatures. A ComplexFeature

[not at google - send to devlin, 2012/12/14 19:10:42]

s/SimpleFeatures/Features/

[justinlin, 2012/12/14 21:07:52]

Done.

+// is available if any SimpleFeature (i.e. permission rule) that composes it is
+// available, but not if only some combination of SimpleFeatures is available.
+class ComplexFeature : public Feature {
+ public:
+  typedef std::vector<SimpleFeature*> FeatureList;

[not at google - send to devlin, 2012/12/14 19:10:42]

std::vector<Feature*> (actually, ScopedVector<SimpleFeature>)

there is no reason why ComplexFeature only supports SimpleFeatures, it can
support any type of Feature.

[justinlin, 2012/12/14 21:07:52]

The "reason" was that GetAvailabilityMessage was a protected member, so
ComplexFeature couldn't call SimpleFeature::GetAvailabilityMessage. Looking at
it again, I guess it's OK to make that a public method of Feature now.

+
+  explicit ComplexFeature(scoped_ptr<FeatureList> features);
+  virtual ~ComplexFeature();
+
+  // extensions::Feature:
+  virtual Availability IsAvailableToManifest(const std::string& extension_id,
+                                             Extension::Type type,
+                                             Location location,
+                                             int manifest_version,
+                                             Platform platform) const OVERRIDE;
+
+  virtual Availability IsAvailableToContext(const Extension* extension,
+                                            Context context,
+                                            Platform platform) const OVERRIDE;
+
+ protected:
+  // extensions::Feature:
+  virtual std::string GetAvailabilityMessage(
+      AvailabilityResult result,
+      Extension::Type type) const OVERRIDE;
+
+  virtual std::set<Context>* contexts() OVERRIDE;
+
+ private:
+  ScopedVector<SimpleFeature> features_;
+
+  DISALLOW_COPY_AND_ASSIGN(ComplexFeature);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_COMMON_EXTENSIONS_FEATURES_COMPLEX_FEATURE_H_