[Extensions] Add a SimpleFeature::Validate function

extensions/common/features/simple_feature.h

 // Copyright 2014 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 EXTENSIONS_COMMON_FEATURES_SIMPLE_FEATURE_H_
 #define EXTENSIONS_COMMON_FEATURES_SIMPLE_FEATURE_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 29 matching lines @@
    private:
     std::string* previous_id_;
 
     DISALLOW_COPY_AND_ASSIGN(ScopedWhitelistForTest);
   };
 
   SimpleFeature();
   ~SimpleFeature() override;
 
   // Parses the JSON representation of a feature into the fields of this object.
-  // Unspecified values in the JSON are not modified in the object. This allows
-  // us to implement inheritance by parsing one value after another. Returns
-  // the error found, or an empty string on success.
-  virtual std::string Parse(const base::DictionaryValue* dictionary);
+  // Note: Validate() should be called after this.
+  void Parse(const base::DictionaryValue* dictionary);
+
+  // Checks whether the feature is valid. Invalid features should not be used.
+  // Subclasses can override to implement specific checking, but should always
+  // call this method as well.
+  virtual bool Validate(std::string* error);
 
   Availability IsAvailableToContext(const Extension* extension,
                                     Context context) const {
     return IsAvailableToContext(extension, context, GURL());
   }
   Availability IsAvailableToContext(const Extension* extension,
                                     Context context,
                                     Platform platform) const {
     return IsAvailableToContext(extension, context, GURL(), platform);
   }
@@ skipping 82 matching lines @@
                                   version_info::Channel channel) const;
 
  private:
   friend class SimpleFeatureTest;
   FRIEND_TEST_ALL_PREFIXES(BaseFeatureProviderTest, ManifestFeatureTypes);
   FRIEND_TEST_ALL_PREFIXES(BaseFeatureProviderTest, PermissionFeatureTypes);
   FRIEND_TEST_ALL_PREFIXES(ExtensionAPITest, DefaultConfigurationFeatures);
   FRIEND_TEST_ALL_PREFIXES(ManifestUnitTest, Extension);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, Blacklist);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, CommandLineSwitch);
+  FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, ComplexFeatureAvailability);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, Context);
+  FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, FeatureValidation);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, HashedIdBlacklist);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, HashedIdWhitelist);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, Inheritance);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, Location);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, ManifestVersion);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, PackageType);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, ParseContexts);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, ParseLocation);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, ParseManifestVersion);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, ParseNull);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, ParsePackageTypes);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, ParsePlatforms);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, ParseWhitelist);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, Platform);
+  FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, SimpleFeatureAvailability);
   FRIEND_TEST_ALL_PREFIXES(SimpleFeatureTest, Whitelist);
 
   // Holds String to Enum value mappings.
   struct Mappings;
 
   static bool IsIdInList(const std::string& extension_id,
                          const std::vector<std::string>& list);
 
   bool MatchesManifestLocation(Manifest::Location manifest_location) const;
 
@@ skipping 12 matching lines @@
   std::vector<Manifest::Type> extension_types_;
   std::vector<Context> contexts_;
   std::vector<Platform> platforms_;
   URLPatternSet matches_;
   Location location_;
   int min_manifest_version_;
   int max_manifest_version_;
   bool component_extensions_auto_granted_;
   std::string command_line_switch_;
   std::unique_ptr<version_info::Channel> channel_;
+  bool internal_;
 
   DISALLOW_COPY_AND_ASSIGN(SimpleFeature);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_FEATURES_SIMPLE_FEATURE_H_