Reduce number of unnamed-type-template-args violations.

ipc/file_descriptor_set_posix.h

 // Copyright (c) 2011 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_FILE_DESCRIPTOR_SET_POSIX_H_
 #define IPC_FILE_DESCRIPTOR_SET_POSIX_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 13 matching lines @@
   FileDescriptorSet();
 
   // This is the maximum number of descriptors per message. We need to know this
   // because the control message kernel interface has to be given a buffer which
   // is large enough to store all the descriptor numbers. Otherwise the kernel
   // tells us that it truncated the control data and the extra descriptors are
   // lost.
   //
   // In debugging mode, it's a fatal error to try and add more than this number
   // of descriptors to a FileDescriptorSet.
-  enum {
+  enum Constants {
     MAX_DESCRIPTORS_PER_MESSAGE = 5,
   };
 
   // ---------------------------------------------------------------------------
   // Interfaces for building during message serialisation...
 
   // Add a descriptor to the end of the set. Returns false iff the set is full.
   bool Add(int fd);
   // Add a descriptor to the end of the set and automatically close it after
   // transmission. Returns false iff the set is full.
@@ skipping 63 matching lines @@
   // This contains the index of the next descriptor which should be consumed.
   // It's used in a couple of ways. Firstly, at destruction we can check that
   // all the descriptors have been read (with GetNthDescriptor). Secondly, we
   // can check that they are read in order.
   mutable unsigned consumed_descriptor_highwater_;
 
   DISALLOW_COPY_AND_ASSIGN(FileDescriptorSet);
 };
 
 #endif  // IPC_FILE_DESCRIPTOR_SET_POSIX_H_