Make PlatformFileForTransit a class on Windows.

ipc/ipc_message_utils.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 "ipc/ipc_message_utils.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/files/file_path.h"
@@ skipping 762 matching lines @@
 void ParamTraits<base::SharedMemoryHandle>::Write(base::Pickle* m,
                                                   const param_type& p) {
   m->WriteBool(p.NeedsBrokering());
 
   if (p.NeedsBrokering()) {
     HandleWin handle_win(p.GetHandle(), HandleWin::DUPLICATE);
     ParamTraits<HandleWin>::Write(m, handle_win);
 
     // If the caller intended to pass ownership to the IPC stack, release a
     // reference.
-    if (p.OwnershipPassesToIPC())
+    if (p.OwnershipPassesToIPC() && p.BelongsToCurrentProcess())
       p.Close();
   } else {
     m->WriteInt(HandleToLong(p.GetHandle()));
   }
 }
 
 bool ParamTraits<base::SharedMemoryHandle>::Read(const base::Pickle* m,
                                                  base::PickleIterator* iter,
                                                  param_type* r) {
   bool needs_brokering;
@@ skipping 424 matching lines @@
   return result;
 }
 
 void ParamTraits<MSG>::Log(const param_type& p, std::string* l) {
   l->append("<MSG>");
 }
 
 #endif  // OS_WIN
 
 }  // namespace IPC