Use SharedMemoryHandle instead ScopedHandle as ivar for SharedMemory

base/memory/shared_memory_mac.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 "base/memory/shared_memory.h"
 
 #include <errno.h>
 #include <mach/mach_vm.h>
 #include <stddef.h>
 #include <sys/mman.h>
@@ skipping 71 matching lines @@
 }  // namespace
 
 SharedMemory::SharedMemory()
     : mapped_memory_mechanism_(SharedMemoryHandle::MACH),
       mapped_size_(0),
       memory_(NULL),
       read_only_(false),
       requested_size_(0) {}
 
 SharedMemory::SharedMemory(const SharedMemoryHandle& handle, bool read_only)
-    : shm_(handle),
-      mapped_memory_mechanism_(SharedMemoryHandle::POSIX),
+    : mapped_memory_mechanism_(SharedMemoryHandle::POSIX),
+      shm_(handle),
       mapped_size_(0),
       memory_(NULL),
       read_only_(read_only),
       requested_size_(0) {}
 
 SharedMemory::~SharedMemory() {
   Unmap();
   Close();
 }
 
@@ skipping 167 matching lines @@
 
   DCHECK(shm_.IsValid());
   base::SharedMemoryHandle new_handle;
   bool success = MakeMachSharedMemoryHandleReadOnly(&new_handle, shm_, memory_);
   if (success)
     new_handle.SetOwnershipPassesToIPC(true);
   return new_handle;
 }
 
 }  // namespace base