Delete the audio modem and copresence private APIs.

components/audio_modem.gypi

-# Copyright 2015 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.
-
-{
-  'targets': [
-    {
-      'target_name': 'audio_modem',
-      'type': 'static_library',
-      'dependencies': [
-        '../base/base.gyp:base',
-        '../content/content.gyp:content_common',
-        '../media/media.gyp:media',
-        '../media/media.gyp:shared_memory_support',
-        '../third_party/webrtc/common_audio/common_audio.gyp:common_audio',
-      ],
-      'include_dirs': [
-        '..',
-      ],
-      'sources': [
-        # Note: sources list duplicated in GN build.
-        'audio_modem/audio_player.h',
-        'audio_modem/audio_player_impl.cc',
-        'audio_modem/audio_player_impl.h',
-        'audio_modem/audio_recorder.h',
-        'audio_modem/audio_recorder_impl.cc',
-        'audio_modem/audio_recorder_impl.h',
-        'audio_modem/constants.cc',
-        'audio_modem/modem_impl.cc',
-        'audio_modem/modem_impl.h',
-        'audio_modem/public/modem.h',
-        'audio_modem/public/audio_modem_types.h',
-        'audio_modem/public/whispernet_client.h',
-        'audio_modem/audio_modem_switches.cc',
-        'audio_modem/audio_modem_switches.h',
-      ],
-    },
-    {
-      'target_name': 'audio_modem_test_support',
-      'type': 'static_library',
-      'include_dirs': [
-        '..',
-      ],
-      'sources': [
-        'audio_modem/test/random_samples.cc',
-        'audio_modem/test/random_samples.h',
-        'audio_modem/test/stub_modem.cc',
-        'audio_modem/test/stub_modem.h',
-        'audio_modem/test/stub_whispernet_client.cc',
-        'audio_modem/test/stub_whispernet_client.h',
-      ],
-    },
-  ],
-}