Reland "Removing forward headers in modules/audio_coding/codecs.""

This reverts commit 1d0b9d04bd8738d3685c41fe3c224372bb3a6a53.

Reason for revert: Downstream projects have been updated.

Original change's description:
> Revert "Removing forward headers in modules/audio_coding/codecs."
> 
> This reverts commit 2279aec00b54fa6f8b55c40255452f0292adb473.
> 
> Reason for revert: breaks downstream project.
> 
> Original change's description:
> > Removing forward headers in modules/audio_coding/codecs.
> > 
> > Bug: webrtc:5805
> > Change-Id: Ie0b1d1d1ef01039bcadbfe42dd67d770d93983a9
> > Reviewed-on: https://webrtc-review.googlesource.com/47382
> > Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
> > Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
> > Cr-Commit-Position: refs/heads/master@{#21870}
> 
> TBR=mbonadei@webrtc.org,kwiberg@webrtc.org
> 
> Change-Id: I35dc09ec1988d3d614d8facd5378a5db70942fb4
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: webrtc:5805
> Reviewed-on: https://webrtc-review.googlesource.com/47520
> Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
> Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#21875}

TBR=mbonadei@webrtc.org,kwiberg@webrtc.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: webrtc:5805
Change-Id: I044537655012062b2a084559e90ca799286e3994
Reviewed-on: https://webrtc-review.googlesource.com/48400
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21905}
diff --git a/api/DEPS b/api/DEPS
index 5ac116c..01a3e73 100644
--- a/api/DEPS
+++ b/api/DEPS
@@ -7,15 +7,6 @@
 ]
 
 specific_include_rules = {
-  # TODO(ossu): Remove this exception when {builtin_,}audio_encoder_factory.h
-  # has moved to api/.
-  "peerconnectioninterface\.h": [
-    "+call/callfactoryinterface.h",
-    "+logging/rtc_event_log/rtc_event_log_factory_interface.h",
-    "+modules/audio_coding/codecs/audio_encoder_factory.h",
-    "+modules/audio_coding/codecs/builtin_audio_encoder_factory.h",
-  ],
-
   # Needed because AudioEncoderOpus is in the wrong place for
   # backwards compatibilty reasons. See
   # https://bugs.chromium.org/p/webrtc/issues/detail?id=7847
diff --git a/modules/audio_coding/BUILD.gn b/modules/audio_coding/BUILD.gn
index 639899d..18f1aba 100644
--- a/modules/audio_coding/BUILD.gn
+++ b/modules/audio_coding/BUILD.gn
@@ -2265,27 +2265,3 @@
     "../../api/audio_codecs:audio_codecs_api",
   ]
 }
-
-# For backwards compatibility only! Use
-# webrtc/api/audio_codecs:builtin_audio_decoder_factory instead.
-# TODO(kwiberg): Remove this.
-rtc_source_set("builtin_audio_decoder_factory") {
-  sources = [
-    "codecs/builtin_audio_decoder_factory.h",
-  ]
-  deps = [
-    "../../api/audio_codecs:builtin_audio_decoder_factory",
-  ]
-}
-
-# For backwards compatibility only! Use
-# webrtc/api/audio_codecs:builtin_audio_decoder_factory instead.
-# TODO(ossu): Remove this.
-rtc_source_set("builtin_audio_encoder_factory") {
-  sources = [
-    "codecs/builtin_audio_encoder_factory.h",
-  ]
-  deps = [
-    "../../api/audio_codecs:builtin_audio_encoder_factory",
-  ]
-}
diff --git a/modules/audio_coding/codecs/builtin_audio_decoder_factory.h b/modules/audio_coding/codecs/builtin_audio_decoder_factory.h
deleted file mode 100644
index 7494ac0..0000000
--- a/modules/audio_coding/codecs/builtin_audio_decoder_factory.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/*
- *  Copyright (c) 2016 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.
- */
-
-// This file is for backwards compatibility only! Use
-// webrtc/api/audio_codecs/builtin_audio_decoder_factory.h instead!
-// TODO(kwiberg): Remove it.
-
-#ifndef MODULES_AUDIO_CODING_CODECS_BUILTIN_AUDIO_DECODER_FACTORY_H_
-#define MODULES_AUDIO_CODING_CODECS_BUILTIN_AUDIO_DECODER_FACTORY_H_
-
-#include "api/audio_codecs/builtin_audio_decoder_factory.h"
-
-#endif  // MODULES_AUDIO_CODING_CODECS_BUILTIN_AUDIO_DECODER_FACTORY_H_
diff --git a/modules/audio_coding/codecs/builtin_audio_encoder_factory.h b/modules/audio_coding/codecs/builtin_audio_encoder_factory.h
deleted file mode 100644
index 6ec765a..0000000
--- a/modules/audio_coding/codecs/builtin_audio_encoder_factory.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/*
- *  Copyright (c) 2016 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.
- */
-
-// This file is for backwards compatibility only! Use
-// webrtc/api/audio_codecs/builtin_audio_decoder_factory.h instead!
-// TODO(ossu): Remove it.
-
-#ifndef MODULES_AUDIO_CODING_CODECS_BUILTIN_AUDIO_ENCODER_FACTORY_H_
-#define MODULES_AUDIO_CODING_CODECS_BUILTIN_AUDIO_ENCODER_FACTORY_H_
-
-#include "api/audio_codecs/builtin_audio_encoder_factory.h"
-
-#endif  // MODULES_AUDIO_CODING_CODECS_BUILTIN_AUDIO_ENCODER_FACTORY_H_
diff --git a/pc/DEPS b/pc/DEPS
index 24cb242..38d40a0 100644
--- a/pc/DEPS
+++ b/pc/DEPS
@@ -22,13 +22,4 @@
   "srtpfilter_unittest\.cc": [
     "+crypto",
   ],
-
-  # TODO(ossu): Remove these exceptions when audio_encoder_factory.h
-  # has moved to api/.
-  "peerconnectionfactory\.cc": [
-    "+modules/audio_coding/codecs/builtin_audio_encoder_factory.h",
-  ],
-  "peerconnectioninterface_unittest\.cc": [
-    "+modules/audio_coding/codecs/builtin_audio_encoder_factory.h",
-  ],
 }