Use an explicit PID for duplicating Pepper handles rather than the Channel's.

ppapi/proxy/plugin_dispatcher.h

 // 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.
 
 #ifndef PPAPI_PROXY_PLUGIN_DISPATCHER_H_
 #define PPAPI_PROXY_PLUGIN_DISPATCHER_H_
 
 #include <set>
 #include <string>
 
@@ skipping 108 matching lines @@
                             PP_LogLevel level,
                             const std::string& source,
                             const std::string& value);
 
   const void* GetPluginInterface(const std::string& interface_name);
 
   // You must call this function before anything else. Returns true on success.
   // The delegate pointer must outlive this class, ownership is not
   // transferred.
   bool InitPluginWithChannel(PluginDelegate* delegate,
+                             base::ProcessId peer_pid,
                              const IPC::ChannelHandle& channel_handle,
                              bool is_client);
 
   // Dispatcher overrides.
   virtual bool IsPlugin() const;
   virtual bool Send(IPC::Message* msg);
 
   // IPC::Listener implementation.
   virtual bool OnMessageReceived(const IPC::Message& msg);
   virtual void OnChannelError();
@@ skipping 67 matching lines @@
   // incognito mode.
   bool incognito_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginDispatcher);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_PLUGIN_DISPATCHER_H_