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

ppapi/proxy/plugin_dispatcher.cc

 // 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.
 
 #include "ppapi/proxy/plugin_dispatcher.h"
 
 #include <map>
 
 #include "base/compiler_specific.h"
 #include "base/logging.h"
@@ skipping 137 matching lines @@
   if (found == plugin_interfaces_.end()) {
     const void* ret = local_get_interface()(interface_name.c_str());
     plugin_interfaces_.insert(std::make_pair(interface_name, ret));
     return ret;
   }
   return found->second;
 }
 
 bool PluginDispatcher::InitPluginWithChannel(
     PluginDelegate* delegate,
+    base::ProcessId peer_pid,
     const IPC::ChannelHandle& channel_handle,
     bool is_client) {
-  if (!Dispatcher::InitWithChannel(delegate, channel_handle, is_client))
+  if (!Dispatcher::InitWithChannel(delegate, peer_pid, channel_handle,
+                                   is_client))
     return false;
   plugin_delegate_ = delegate;
   plugin_dispatcher_id_ = plugin_delegate_->Register(this);
 
   // The message filter will intercept and process certain messages directly
   // on the I/O thread.
   channel()->AddFilter(
       new PluginMessageFilter(delegate->GetGloballySeenInstanceIDSet()));
   return true;
 }
@@ skipping 175 matching lines @@
     DLOG_IF(INFO, reply_params.sequence() != 0)
         << "Pepper resource reply message received but the resource doesn't "
            "exist (probably has been destroyed).";
     return;
   }
   resource->OnReplyReceived(reply_params, nested_msg);
 }
 
 }  // namespace proxy
 }  // namespace ppapi