[Extensions Bindings] Introduce BindingAccessChecker

extensions/renderer/api_binding.h

 // Copyright 2016 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_RENDERER_API_BINDING_H_
 #define EXTENSIONS_RENDERER_API_BINDING_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 12 matching lines @@
 namespace gin {
 class Arguments;
 }
 
 namespace extensions {
 class APIBindingHooks;
 class APIEventHandler;
 class APIRequestHandler;
 class APISignature;
 class APITypeReferenceMap;
+class BindingAccessChecker;
 
 namespace binding {
 enum class RequestThread;
 }
 
 // A class that vends v8::Objects for extension APIs. These APIs have function
 // interceptors for all exposed methods, which call back into the APIBinding.
 // The APIBinding then matches the calling arguments against an expected method
 // signature, throwing an error if they don't match.
 // There should only need to be a single APIBinding object for each API, and
 // each can vend multiple v8::Objects for different contexts.
 // This object is designed to be one-per-isolate, but used across separate
 // contexts.
 class APIBinding {
  public:
   using CreateCustomType = base::Callback<v8::Local<v8::Object>(
       v8::Isolate* isolate,
       const std::string& type_name,
       const std::string& property_name,
       const base::ListValue* property_values)>;
 
-  // The callback for determining if a given API feature (specified by |name|)
-  // is available in the given context.
-  using AvailabilityCallback =
-      base::Callback<bool(v8::Local<v8::Context>, const std::string& name)>;
-
   // The callback type for handling an API call.
   using HandlerCallback = base::Callback<void(gin::Arguments*)>;
 
   // The APITypeReferenceMap is required to outlive this object.
   // |function_definitions|, |type_definitions| and |event_definitions|
   // may be null if the API does not specify any of that category.
   APIBinding(const std::string& name,
              const base::ListValue* function_definitions,
              const base::ListValue* type_definitions,
              const base::ListValue* event_definitions,
              const base::DictionaryValue* property_definitions,
              const CreateCustomType& create_custom_type,
-             const AvailabilityCallback& is_available,
              std::unique_ptr<APIBindingHooks> binding_hooks,
              APITypeReferenceMap* type_refs,
              APIRequestHandler* request_handler,
-             APIEventHandler* event_handler);
+             APIEventHandler* event_handler,
+             BindingAccessChecker* access_checker);
   ~APIBinding();
 
   // Returns a new v8::Object for the API this APIBinding represents.
   v8::Local<v8::Object> CreateInstance(v8::Local<v8::Context> context);
 
   APIBindingHooks* hooks() { return binding_hooks_.get(); }
 
  private:
   // Initializes the object_template_ for this API. Called lazily when the
   // first instance is created.
@@ skipping 42 matching lines @@
   using EnumEntry = std::pair<std::string, std::string>;
   // A map of <name, values> for the enums on this API.
   std::map<std::string, std::vector<EnumEntry>> enums_;
 
   // The associated properties of the API, if any.
   const base::DictionaryValue* property_definitions_;
 
   // The callback for constructing a custom type.
   CreateCustomType create_custom_type_;
 
-  // The callback for checking availability of an API feature.
-  AvailabilityCallback is_available_;
-
   // The registered hooks for this API.
   std::unique_ptr<APIBindingHooks> binding_hooks_;
 
   // The reference map for all known types; required to outlive this object.
   APITypeReferenceMap* type_refs_;
 
   // The associated request handler, shared between this and other bindings.
   // Required to outlive this object.
   APIRequestHandler* request_handler_;
 
   // The associated event handler, shared between this and other bindings.
   // Required to outlive this object.
   APIEventHandler* event_handler_;
 
+  // The associated access checker; required to outlive this object.
+  const BindingAccessChecker* const access_checker_;
+
   // The template for this API. Note: some methods may only be available in
   // certain contexts, but this template contains all methods. Those that are
   // unavailable are removed after object instantiation.
   v8::Eternal<v8::ObjectTemplate> object_template_;
 
   base::WeakPtrFactory<APIBinding> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(APIBinding);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_API_BINDING_H_