[extension SW]: Support event listener registration and event dispatching.

extensions/renderer/event_bindings.h

 // Copyright 2014 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_BINDINGS_H_
 #define EXTENSIONS_RENDERER_EVENT_BINDINGS_H_
 
 #include <memory>
 #include <set>
 #include <string>
 
 #include "base/macros.h"
 #include "extensions/renderer/object_backed_native_handler.h"
 #include "v8/include/v8.h"
 
+namespace IPC {
+class Sender;
+}
+
 namespace base {
 class DictionaryValue;
 }
 
 namespace extensions {
 class EventMatcher;
 
 // This class deals with the javascript bindings related to Event objects.
 class EventBindings : public ObjectBackedNativeHandler {
  public:
@@ skipping 40 matching lines @@
   // |matcher_id| The ID of the filtered event.
   // |is_manual| false if this is part of the extension unload process where all
   // listeners are automatically detached.
   void DetachFilteredEvent(int matcher_id, bool is_manual);
 
   void MatchAgainstEventFilter(const v8::FunctionCallbackInfo<v8::Value>& args);
 
   std::unique_ptr<EventMatcher> ParseEventMatcher(
       std::unique_ptr<base::DictionaryValue> filter);
 
+  IPC::Sender* GetIPCSender();
+
   // Called when our context, and therefore us, is invalidated. Run any cleanup.
   void OnInvalidated();
 
   // The set of attached events and filtered events. Maintain these so that we
   // can detch them on unload.
   std::set<std::string> attached_event_names_;
   std::set<int> attached_matcher_ids_;
 
   DISALLOW_COPY_AND_ASSIGN(EventBindings);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_EVENT_BINDINGS_H_