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

ipc/ipc_channel_posix.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_posix.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <stddef.h>
 #include <sys/socket.h>
@@ skipping 539 matching lines @@
   }
 
   return true;
 }
 
 int ChannelPosix::GetClientFileDescriptor() const {
   base::AutoLock lock(client_pipe_lock_);
   return client_pipe_.get();
 }
 
-int ChannelPosix::TakeClientFileDescriptor() {
+base::ScopedFD ChannelPosix::TakeClientFileDescriptor() {
   base::AutoLock lock(client_pipe_lock_);
   if (!client_pipe_.is_valid())
-    return -1;
+    return base::ScopedFD();
   PipeMap::GetInstance()->Remove(pipe_name_);
-  return client_pipe_.release();
+  return client_pipe_.Pass();
 }
 
 void ChannelPosix::CloseClientFileDescriptor() {
   base::AutoLock lock(client_pipe_lock_);
   if (!client_pipe_.is_valid())
     return;
   PipeMap::GetInstance()->Remove(pipe_name_);
   client_pipe_.reset();
 }
 
@@ skipping 500 matching lines @@
 }
 
 #if defined(OS_LINUX)
 // static
 void Channel::SetGlobalPid(int pid) {
   ChannelPosix::SetGlobalPid(pid);
 }
 #endif  // OS_LINUX
 
 }  // namespace IPC