Add ipc_channel_nacl to the untrusted build and fix all compile/link errors.

ipc/ipc_channel.h

 // 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.
 
 #ifndef IPC_IPC_CHANNEL_H_
 #define IPC_IPC_CHANNEL_H_
 #pragma once
 
 #include <string>
 
@@ skipping 142 matching lines @@
   // Get the process ID for the connected peer.
   // Returns base::kNullProcessId if the peer is not connected yet.
   base::ProcessId peer_pid() const;
 
   // Send a message over the Channel to the listener on the other end.
   //
   // |message| must be allocated using operator new.  This object will be
   // deleted once the contents of the Message have been sent.
   virtual bool Send(Message* message) OVERRIDE;
 
-#if defined(OS_POSIX) && !defined(OS_NACL)
+#if defined(OS_POSIX)
   // On POSIX an IPC::Channel wraps a socketpair(), this method returns the
   // FD # for the client end of the socket.
   // This method may only be called on the server side of a channel.
   // This method can be called on any thread.
   int GetClientFileDescriptor() const;
 
   // Same as GetClientFileDescriptor, but transfers the ownership of the
   // file descriptor to the caller.
   // This method can be called on any thread.
   int TakeClientFileDescriptor();
@@ skipping 48 matching lines @@
 
  private:
   // PIMPL to which all channel calls are delegated.
   class ChannelImpl;
   ChannelImpl *channel_impl_;
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_H_