[Extensions Bindings] Add a bindings/ subdirectory under renderer

extensions/renderer/event_emitter.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_EVENT_EMITTER_H_
-#define EXTENSIONS_RENDERER_EVENT_EMITTER_H_
-
-#include <vector>
-
-#include "extensions/renderer/api_binding_types.h"
-#include "gin/wrappable.h"
-#include "v8/include/v8.h"
-
-namespace gin {
-class Arguments;
-}
-
-namespace extensions {
-class APIEventListeners;
-struct EventFilteringInfo;
-
-// A gin::Wrappable Event object. One is expected to be created per event, per
-// context. Note: this object *does not* clear any events, so it must be
-// destroyed with the context to avoid leaking.
-class EventEmitter final : public gin::Wrappable<EventEmitter> {
- public:
-  EventEmitter(bool supports_filters,
-               std::unique_ptr<APIEventListeners> listeners,
-               const binding::RunJSFunction& run_js,
-               const binding::RunJSFunctionSync& run_js_sync);
-  ~EventEmitter() override;
-
-  static gin::WrapperInfo kWrapperInfo;
-
-  // gin::Wrappable:
-  gin::ObjectTemplateBuilder GetObjectTemplateBuilder(
-      v8::Isolate* isolate) final;
-
-  void Fire(v8::Local<v8::Context> context,
-            std::vector<v8::Local<v8::Value>>* args,
-            const EventFilteringInfo* filter);
-
-  // Removes all listeners and marks this object as invalid so that no more
-  // are added.
-  void Invalidate(v8::Local<v8::Context> context);
-
-  // TODO(devlin): Consider making this a test-only method and exposing
-  // HasListeners() instead.
-  size_t GetNumListeners() const;
-
- private:
-  // Bound methods for the Event JS object.
-  void AddListener(gin::Arguments* arguments);
-  void RemoveListener(gin::Arguments* arguments);
-  bool HasListener(v8::Local<v8::Function> function);
-  bool HasListeners();
-  void Dispatch(gin::Arguments* arguments);
-
-  // Notifies the listeners of an event with the given |args|. If |run_sync| is
-  // true, runs JS synchronously and populates |out_values| with the results of
-  // the listeners.
-  void DispatchImpl(v8::Local<v8::Context> context,
-                    std::vector<v8::Local<v8::Value>>* args,
-                    const EventFilteringInfo* filter,
-                    bool run_sync,
-                    std::vector<v8::Global<v8::Value>>* out_values);
-
-  // Whether or not this object is still valid; false upon context release.
-  // When invalid, no listeners can be added or removed.
-  bool valid_ = true;
-
-  // Whether the event supports filters.
-  bool supports_filters_ = false;
-
-  std::unique_ptr<APIEventListeners> listeners_;
-
-  binding::RunJSFunction run_js_;
-  binding::RunJSFunctionSync run_js_sync_;
-
-  DISALLOW_COPY_AND_ASSIGN(EventEmitter);
-};
-
-}  // namespace extensions
-
-#endif  // EXTENSIONS_RENDERER_EVENT_EMITTER_H_