Remove nogncheck from pc/.

The usage of "nogncheck" is disallowed in WebRTC (the only exception is
for the "#includes" that are part of conditional compilation with the
preprocessor).

This CL removes some "nogncheck" from the pc/ folder. The included
headers were unused so this should be a no-op change.

Bug: webrtc:8733
Change-Id: I22f5238bbc08aa500d4f0850e30acfbaed9742ae
Reviewed-on: https://webrtc-review.googlesource.com/c/120929
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26528}
diff --git a/pc/channel.cc b/pc/channel.cc
index e5b6bb0..0e91395 100644
--- a/pc/channel.cc
+++ b/pc/channel.cc
@@ -28,9 +28,6 @@
 #include "rtc_base/network_route.h"
 #include "rtc_base/strings/string_builder.h"
 #include "rtc_base/trace_event.h"
-// Adding 'nogncheck' to disable the gn include headers check to support modular
-// WebRTC build targets.
-#include "media/engine/webrtc_voice_engine.h"  // nogncheck
 #include "p2p/base/packet_transport_internal.h"
 #include "pc/channel_manager.h"
 #include "pc/rtp_media_utils.h"
diff --git a/pc/peer_connection_factory.cc b/pc/peer_connection_factory.cc
index f8e5911..5fcf43d 100644
--- a/pc/peer_connection_factory.cc
+++ b/pc/peer_connection_factory.cc
@@ -29,12 +29,6 @@
 #include "pc/rtp_parameters_conversion.h"
 #include "rtc_base/bind.h"
 #include "rtc_base/checks.h"
-// Adding 'nogncheck' to disable the gn include headers check to support modular
-// WebRTC build targets.
-// TODO(zhihuang): This wouldn't be necessary if the interface and
-// implementation of the media engine were in separate build targets.
-#include "media/engine/webrtc_media_engine.h"           // nogncheck
-#include "modules/audio_device/include/audio_device.h"  // nogncheck
 #include "p2p/base/basic_packet_socket_factory.h"
 #include "p2p/client/basic_port_allocator.h"
 #include "pc/audio_track.h"