[Extensions Bindings] Add ChromeSetting custom type

extensions/renderer/chrome_setting.h

+// Copyright 2017 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_CHROME_SETTING_H_
+#define EXTENSIONS_RENDERER_CHROME_SETTING_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "extensions/renderer/argument_spec.h"
+#include "gin/wrappable.h"
+#include "v8/include/v8.h"
+
+namespace base {
+class DictionaryValue;
+}
+
+namespace gin {
+class Arguments;
+}
+
+namespace extensions {
+class APIEventHandler;
+class APIRequestHandler;
+
+// The custom implementation of the ChromeSetting type exposed to APIs.
+class ChromeSetting final : public gin::Wrappable<ChromeSetting> {
+ public:
+  ~ChromeSetting() override;
+
+  // Creates a ChromeSetting object for the given property.
+  static v8::Local<v8::Object> Create(v8::Local<v8::Context> context,
+                                      const std::string& property_name,
+                                      APIRequestHandler* request_handler,
+                                      APIEventHandler* event_handler,
+                                      APITypeReferenceMap* type_refs);
+
+  static gin::WrapperInfo kWrapperInfo;
+
+  gin::ObjectTemplateBuilder GetObjectTemplateBuilder(
+      v8::Isolate* isolate) override;
+
+ private:
+  ChromeSetting(APIRequestHandler* request_handler,
+                APIEventHandler* event_handler,
+                const APITypeReferenceMap* type_refs,
+                const std::string& pref_name,
+                const base::DictionaryValue& argument_spec);
+
+  // JS function handlers:
+  void Get(gin::Arguments* arguments);
+  void Set(gin::Arguments* arguments);
+  void Clear(gin::Arguments* arguments);
+
+  // Returns the onChange event associated with the ChromeSetting.
+  v8::Local<v8::Value> GetOnChangeEvent(gin::Arguments* arguments);
+
+  // Common function handling endpoint.
+  void HandleFunction(const std::string& function_name,
+                      gin::Arguments* arguments);
+
+  APIRequestHandler* request_handler_;
+
+  APIEventHandler* event_handler_;
+
+  const APITypeReferenceMap* type_refs_;
+
+  // The name of the preference this ChromeSetting is managing.
+  std::string pref_name_;
+
+  // The type of argument that calling set() on the ChromeSetting expects (since
+  // different settings can take a different type of argument depending on the
+  // preference it manages).
+  ArgumentSpec argument_spec_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeSetting);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_RENDERER_CHROME_SETTING_H_