Add a sandbox API for broker handle duplication

content/plugin/plugin_channel.h

Index: content/plugin/plugin_channel.h
===================================================================
--- content/plugin/plugin_channel.h	(revision 128951)
+++ content/plugin/plugin_channel.h	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -36,7 +36,6 @@
   virtual bool Send(IPC::Message* msg) OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
-  base::ProcessHandle renderer_handle() const { return renderer_handle_; }
   int renderer_id() { return renderer_id_; }
 
   virtual int GenerateRouteID() OVERRIDE;
@@ -59,7 +58,6 @@
 
  protected:
   // IPC::Channel::Listener implementation:
-  virtual void OnChannelConnected(int32 peer_pid) OVERRIDE;
   virtual void OnChannelError() OVERRIDE;
 
   virtual void CleanUp() OVERRIDE;
@@ -88,9 +86,6 @@
 
   std::vector<scoped_refptr<WebPluginDelegateStub> > plugin_stubs_;
 
-  // Handle to the renderer process who is on the other side of the channel.
-  base::ProcessHandle renderer_handle_;
-
   // The id of the renderer who is on the other side of the channel.
   int renderer_id_;