Only deliver extension messages to contexts that care.

chrome/browser/extensions/extension_message_service.h

 // Copyright (c) 2011 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 CHROME_BROWSER_EXTENSIONS_EXTENSION_MESSAGE_SERVICE_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_MESSAGE_SERVICE_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 38 matching lines @@
       public NotificationObserver {
  public:
   // A messaging channel. Note that the opening port can be the same as the
   // receiver, if an extension toolstrip wants to talk to its tab (for example).
   struct MessageChannel;
   struct MessagePort;
 
   // Javascript function name constants.
   static const char kDispatchOnConnect[];
   static const char kDispatchOnDisconnect[];
-  static const char kDispatchOnMessage[];
 
   // Allocates a pair of port ids.
   // NOTE: this can be called from any thread.
   static void AllocatePortIdPair(int* port1, int* port2);
 
   explicit ExtensionMessageService(Profile* profile);
 
   // Notification that our owning profile is going away.
   void DestroyingProfile();
 
@@ skipping 75 matching lines @@
   Profile* profile_;
 
   NotificationRegistrar registrar_;
 
   MessageChannelMap channels_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionMessageService);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_MESSAGE_SERVICE_H_