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

extensions/browser/extension_message_filter.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_BROWSER_EXTENSION_MESSAGE_FILTER_H_
 #define EXTENSIONS_BROWSER_EXTENSION_MESSAGE_FILTER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 36 matching lines @@
 
   // content::BrowserMessageFilter implementation:
   void OverrideThreadForMessage(const IPC::Message& message,
                                 content::BrowserThread::ID* thread) override;
   void OnDestruct() const override;
   bool OnMessageReceived(const IPC::Message& message) override;
 
   // Message handlers on the UI thread.
   void OnExtensionAddListener(const std::string& extension_id,
                               const GURL& listener_url,
-                              const std::string& event_name);
+                              const std::string& event_name,
+                              int worker_thread_id);
   void OnExtensionRemoveListener(const std::string& extension_id,
                                  const GURL& listener_url,
-                                 const std::string& event_name);
+                                 const std::string& event_name,
+                                 int worker_thread_id);
   void OnExtensionAddLazyListener(const std::string& extension_id,
-                                  const std::string& event_name);
+                                  const std::string& event_name,
+                                  int worker_thread_id);
   void OnExtensionRemoveLazyListener(const std::string& extension_id,
-                                     const std::string& event_name);
+                                     const std::string& event_name,
+                                     int worker_thread_id);
   void OnExtensionAddFilteredListener(const std::string& extension_id,
                                       const std::string& event_name,
                                       const base::DictionaryValue& filter,
                                       bool lazy);
   void OnExtensionRemoveFilteredListener(const std::string& extension_id,
                                          const std::string& event_name,
                                          const base::DictionaryValue& filter,
                                          bool lazy);
   void OnExtensionShouldSuspendAck(const std::string& extension_id,
                                    int sequence_id);
@@ skipping 12 matching lines @@
 
   // Only access from the UI thread.
   content::BrowserContext* browser_context_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionMessageFilter);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_EXTENSION_MESSAGE_FILTER_H_