Refactoring: Make IPC::Channel::TakeClientFileDescriptor() a ScopedFD.

ipc/ipc_channel_proxy.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_channel_proxy.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/location.h"
 #include "base/memory/ref_counted.h"
@@ skipping 428 matching lines @@
 // ChannelProxy::Init().
 int ChannelProxy::GetClientFileDescriptor() {
   DCHECK(CalledOnValidThread());
 
   Channel* channel = context_.get()->channel_.get();
   // Channel must have been created first.
   DCHECK(channel) << context_.get()->channel_id_;
   return channel->GetClientFileDescriptor();
 }
 
-int ChannelProxy::TakeClientFileDescriptor() {
+base::ScopedFD ChannelProxy::TakeClientFileDescriptor() {
   DCHECK(CalledOnValidThread());
 
   Channel* channel = context_.get()->channel_.get();
   // Channel must have been created first.
   DCHECK(channel) << context_.get()->channel_id_;
   return channel->TakeClientFileDescriptor();
 }
 #endif
 
 //-----------------------------------------------------------------------------
 
 }  // namespace IPC