[Extensions Bindings] Add support for custom property types

extensions/renderer/api_bindings_system.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_BINDINGS_SYSTEM_H_
 #define EXTENSIONS_RENDERER_API_BINDINGS_SYSTEM_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 15 matching lines @@
 namespace extensions {
 class APIRequestHandler;
 
 // A class encompassing the necessary pieces to construct the JS entry points
 // for Extension APIs. Designed to be used on a single thread, but safe between
 // multiple v8::Contexts.
 class APIBindingsSystem {
  public:
   using GetAPISchemaMethod =
       base::Callback<const base::DictionaryValue&(const std::string&)>;
+  using CustomTypeHandler =
+      base::Callback<v8::Local<v8::Object>(v8::Local<v8::Context> context,
+                                           const std::string& property_name,
+                                           APIRequestHandler* request_handler,
+                                           APITypeReferenceMap* type_refs)>;
 
   APIBindingsSystem(const binding::RunJSFunction& call_js,
                     const binding::RunJSFunctionSync& call_js_sync,
                     const GetAPISchemaMethod& get_api_schema,
                     const APIRequestHandler::SendRequestMethod& send_request,
                     const APIEventHandler::EventListenersChangedMethod&
                         event_listeners_changed,
                     APILastError last_error);
   ~APIBindingsSystem();
 
@@ skipping 19 matching lines @@
 
   // Returns the APIBindingHooks object for the given api to allow for
   // registering custom hooks. These must be registered *before* the
   // binding is instantiated.
   // TODO(devlin): It's a little weird that we don't just expose a
   // RegisterHooks-type method. Depending on how complex the hook interface
   // is, maybe we should rethink this. Downside would be that it's less
   // efficient to register multiple hooks for the same API.
   APIBindingHooks* GetHooksForAPI(const std::string& api_name);
 
+  // Registers the handler for creating a custom type with the given
+  // |type_name|.
+  void RegisterCustomType(const std::string& type_name,
+                          const CustomTypeHandler& function);
+
  private:
   // Creates a new APIBinding for the given |api_name|.
   std::unique_ptr<APIBinding> CreateNewAPIBinding(const std::string& api_name);
 
   // Callback for the APITypeReferenceMap in order to initialize an unknown
   // type.
   void InitializeType(const std::string& name);
 
+  // Handles creating the type for the specified property.
+  v8::Local<v8::Object> CreateCustomType(v8::Local<v8::Context> context,
+                                         const std::string& type_name,
+                                         const std::string& property_name);
+
   // The map of cached API reference types.
   APITypeReferenceMap type_reference_map_;
 
   // The request handler associated with the system.
   APIRequestHandler request_handler_;
 
   // The event handler associated with the system.
   APIEventHandler event_handler_;
 
   // A map from api_name -> APIBinding for constructed APIs. APIBindings are
   // created lazily.
   std::map<std::string, std::unique_ptr<APIBinding>> api_bindings_;
 
   // A map from api_name -> APIBindingHooks for registering custom hooks.
   // TODO(devlin): This map is pretty pointer-y. Is that going to be a
   // performance concern?
   std::map<std::string, std::unique_ptr<APIBindingHooks>> binding_hooks_;
 
+  std::map<std::string, CustomTypeHandler> custom_types_;
+
   binding::RunJSFunction call_js_;
 
   binding::RunJSFunctionSync call_js_sync_;
 
   // The method to retrieve the DictionaryValue describing a given extension
   // API. Curried in for testing purposes so we can use fake APIs.
   GetAPISchemaMethod get_api_schema_;
 
   DISALLOW_COPY_AND_ASSIGN(APIBindingsSystem);
 };
 
 }  // namespace
 
 #endif  // EXTENSIONS_RENDERER_API_BINDINGS_SYSTEM_H_