[Extensions] Add a SimpleFeature::Validate function

extensions/common/features/permission_feature.h

Index: extensions/common/features/permission_feature.h
diff --git a/extensions/common/features/permission_feature.h b/extensions/common/features/permission_feature.h
index ff4a0ad9c089f1297569e5d369643e1d7a877544..95d889b8b05400b6c2c9cd90efc34e89f783d751 100644
--- a/extensions/common/features/permission_feature.h
+++ b/extensions/common/features/permission_feature.h
@@ -21,8 +21,7 @@ class PermissionFeature : public SimpleFeature {
       Feature::Context context,
       const GURL& url,
       Feature::Platform platform) const override;
-
-  std::string Parse(const base::DictionaryValue* value) override;
+  bool Validate(std::string* error) override;
 };
 
 }  // namespace extensions