Only deliver extension messages to contexts that care.

chrome/renderer/extensions/renderer_extension_bindings.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_RENDERER_EXTENSIONS_RENDERER_EXTENSION_BINDINGS_H_
 #define CHROME_RENDERER_EXTENSIONS_RENDERER_EXTENSION_BINDINGS_H_
 #pragma once
 
+#include <string>
+
 class ExtensionDispatcher;
+class RenderView;
 
 namespace v8 {
 class Extension;
 }
 
 // This class adds extension-related javascript bindings to a renderer.  It is
 // used by both web renderers and extension processes.
 class RendererExtensionBindings {
  public:
   // Name of extension, for dependencies.
   static const char* kName;
 
   // Creates an instance of the extension.
   static v8::Extension* Get(ExtensionDispatcher* dispatcher);
+
+  // Delivers a message sent using content script messaging. If
+  // restrict_to_render_view is specified, only contexts in that render view
+  // will receive the message.
+  static void DeliverMessage(int target_port_id, const std::string& message,
+                             RenderView* restrict_to_render_view);
 };
 
 #endif  // CHROME_RENDERER_EXTENSIONS_RENDERER_EXTENSION_BINDINGS_H_