Convert the PluginResource to be refcounted.

ppapi/proxy/ppb_file_chooser_proxy.cc

 // 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.
 
 #include "ppapi/proxy/ppb_file_chooser_proxy.h"
 
 #include <queue>
 
 #include "ppapi/c/dev/ppb_file_chooser_dev.h"
 #include "ppapi/c/pp_errors.h"
@@ skipping 145 matching lines @@
 
   HostResource result;
   dispatcher->Send(new PpapiHostMsg_PPBFileChooser_Create(
       INTERFACE_ID_PPB_FILE_CHOOSER, instance,
       options->mode,
       options->accept_mime_types ? options->accept_mime_types : std::string(),
       &result));
 
   if (result.is_null())
     return 0;
-  linked_ptr<FileChooser> object(new FileChooser(result));
-  return PluginResourceTracker::GetInstance()->AddResource(object);
+  return PluginResourceTracker::GetInstance()->AddResource(
+      new FileChooser(result));
 }
 
 bool PPB_FileChooser_Proxy::OnMessageReceived(const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PPB_FileChooser_Proxy, msg)
     // Plugin -> host messages.
     IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBFileChooser_Create, OnMsgCreate)
     IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBFileChooser_Show, OnMsgShow)
 
     // Host -> plugin messages.
@@ skipping 54 matching lines @@
       files.push_back(cur_create_info);
     }
   }
 
   dispatcher()->Send(new PpapiMsg_PPBFileChooser_ChooseComplete(
       INTERFACE_ID_PPB_FILE_CHOOSER, chooser, result, files));
 }
 
 }  // namespace proxy
 }  // namespace pp