Remove default_neteq_factory.h backwards compatible header.

Bug: None
Change-Id: I5935ce49d584ee03bbb8118edfc0abf46c9728e8
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/363943
Commit-Queue: Henrik Lundin <henrik.lundin@webrtc.org>
Auto-Submit: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#43103}
diff --git a/modules/audio_coding/BUILD.gn b/modules/audio_coding/BUILD.gn
index 8a882de..c77719a 100644
--- a/modules/audio_coding/BUILD.gn
+++ b/modules/audio_coding/BUILD.gn
@@ -731,12 +731,6 @@
   ]
 }
 
-rtc_source_set("default_neteq_factory") {
-  visibility += webrtc_default_visibility
-  sources = [ "neteq/default_neteq_factory.h" ]
-  deps = [ "../../api/neteq:default_neteq_factory" ]
-}
-
 # Although providing only test support, this target must be outside of the
 # rtc_include_tests conditional. The reason is that it supports fuzzer tests
 # that ultimately are built and run as a part of the Chromium ecosystem, which
diff --git a/modules/audio_coding/neteq/default_neteq_factory.h b/modules/audio_coding/neteq/default_neteq_factory.h
deleted file mode 100644
index 103361d..0000000
--- a/modules/audio_coding/neteq/default_neteq_factory.h
+++ /dev/null
@@ -1,16 +0,0 @@
-/*
- *  Copyright (c) 2019 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.
- */
-
-#ifndef MODULES_AUDIO_CODING_NETEQ_DEFAULT_NETEQ_FACTORY_H_
-#define MODULES_AUDIO_CODING_NETEQ_DEFAULT_NETEQ_FACTORY_H_
-
-#include "api/neteq/default_neteq_factory.h"
-
-#endif  // MODULES_AUDIO_CODING_NETEQ_DEFAULT_NETEQ_FACTORY_H_