Fix "unused variable" warnings.

ipc/ipc_channel_win.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_WIN_H_
 #define IPC_IPC_CHANNEL_WIN_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 103 matching lines @@
   bool waiting_connect_;
 
   // This flag is set when processing incoming messages.  It is used to
   // avoid recursing through ProcessIncomingMessages, which could cause
   // problems.  TODO(darin): make this unnecessary
   bool processing_incoming_;
 
   // Determines if we should validate a client's secret on connection.
   bool validate_client_;
 
-  // Tracks the lifetime of this object, for debugging purposes.
-  uint32_t debug_flags_;
-
   // This is a unique per-channel value used to authenticate the client end of
   // a connection. If the value is non-zero, the client passes it in the hello
   // and the host validates. (We don't send the zero value fto preserve IPC
   // compatability with existing clients that don't validate the channel.)
   int32_t client_secret_;
 
   std::unique_ptr<base::ThreadChecker> thread_check_;
 
   base::WeakPtrFactory<ChannelWin> weak_factory_;
   DISALLOW_COPY_AND_ASSIGN(ChannelWin);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_WIN_H_