FileWrapper[Impl] modifications and actually remove the "Impl" class.

webrtc/system_wrappers/include/trace.h

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  *
  *  System independent wrapper for logging runtime information to file.
@@ skipping 42 matching lines @@
 
   // Returns what type of messages are written to the trace file.
   static int level_filter();
 
   // Sets the file name. If add_file_counter is false the same file will be
   // reused when it fills up. If it's true a new file with incremented name
   // will be used.
   static int32_t SetTraceFile(const char* file_name,
                               const bool add_file_counter = false);
 
-  // Returns the name of the file that the trace is currently writing to.
-  static int32_t TraceFile(char file_name[1024]);
-
   // Registers callback to receive trace messages.
   // TODO(hellner): Why not use OutStream instead? Why is TraceCallback not
   // defined in this file?
   static int32_t SetTraceCallback(TraceCallback* callback);
 
   // Adds a trace message for writing to file. The message is put in a queue
   // for writing to file whenever possible for performance reasons. I.e. there
   // is a crash it is possible that the last, vital logs are not logged yet.
   // level is the type of message to log. If that type of messages is
   // filtered it will not be written to file. module is an identifier for what
   // part of the code the message is coming.
   // id is an identifier that should be unique for that set of classes that
   // are associated (e.g. all instances owned by an engine).
   // msg and the ellipsis are the same as e.g. sprintf.
   // TODO(hellner) Why is TraceModule not defined in this file?
   static void Add(const TraceLevel level,
                   const TraceModule module,
                   const int32_t id,
                   const char* msg, ...);
 
  private:
   static volatile int level_filter_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_SYSTEM_WRAPPERS_INCLUDE_TRACE_H_