Linux: remove unmaintained SELinux code.

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 823 matching lines @@
   }
 
   if (header_fds > FileDescriptorSet::kMaxDescriptorsPerMessage)
     error = "Message requires an excessive number of descriptors";
 
   if (error) {
     LOG(WARNING) << error
                  << " channel:" << this
                  << " message-type:" << msg->type()
                  << " header()->num_fds:" << header_fds;
-#if defined(CHROMIUM_SELINUX)
-    LOG(WARNING) << "In the case of SELinux this can be caused when "
-                    "using a --user-data-dir to which the default "
-                    "policy doesn't give the renderer access to. ";
-#endif  // CHROMIUM_SELINUX
     // Abort the connection.
     ClearInputFDs();
     return false;
   }
 
   // The shenaniganery below with &foo.front() requires input_fds_ to have
   // contiguous underlying storage (such as a simple array or a std::vector).
   // This is why the header warns not to make input_fds_ a deque<>.
   msg->file_descriptor_set()->SetDescriptors(&input_fds_.front(),
                                              header_fds);
@@ skipping 165 matching lines @@
 
 
 #if defined(OS_LINUX)
 // static
 void Channel::SetGlobalPid(int pid) {
   ChannelImpl::SetGlobalPid(pid);
 }
 #endif  // OS_LINUX
 
 }  // namespace IPC