NetEq: Rename Nack to NackTracker to avoid name collisions in GN

webrtc/modules/audio_coding/neteq/neteq.gypi

 # 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.
 
 {
   'variables': {
@@ skipping 82 matching lines @@
         'dsp_helper.cc',
         'dsp_helper.h',
         'dtmf_buffer.cc',
         'dtmf_buffer.h',
         'dtmf_tone_generator.cc',
         'dtmf_tone_generator.h',
         'expand.cc',
         'expand.h',
         'merge.cc',
         'merge.h',
-        'nack.h',
-        'nack.cc',
+        'nack_tracker.h',
+        'nack_tracker.cc',
         'neteq_impl.cc',
         'neteq_impl.h',
         'neteq.cc',
         'statistics_calculator.cc',
         'statistics_calculator.h',
         'normal.cc',
         'normal.h',
         'packet.cc',
         'packet.h',
         'packet_buffer.cc',
@@ skipping 95 matching lines @@
             'tools/rtp_file_source.cc',
             'tools/rtp_file_source.h',
             'tools/rtp_generator.cc',
             'tools/rtp_generator.h',
           ],
         }, # neteq_unittest_tools
       ], # targets
     }], # include_tests
   ], # conditions
 }