Move remaining traces of VoiceEngine

- Move files from voice_engine/ to audio/.
- Rename voice_engine/utility.* to remix_resample.* since there are no other
  utilities in those files.
- Move test/mock_voe_channel_proxy.h to audio/.
- Removed voe_channel_id from Audio[Receive|Send]Stream::Config.
- Remove VoiceEngine* from AudioState::Config.
- Fix a few cpplint complaints which showed when moving files.

NOPRESUBMIT=true

Bug: webrtc:4690
Change-Id: Id266c822d956625c358fa5e193e6f4837164aef8
Reviewed-on: https://webrtc-review.googlesource.com/39268
Commit-Queue: Fredrik Solenberg <solenberg@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21657}
diff --git a/audio/BUILD.gn b/audio/BUILD.gn
index d3af836..2eee20b 100644
--- a/audio/BUILD.gn
+++ b/audio/BUILD.gn
@@ -14,6 +14,8 @@
 
 rtc_static_library("audio") {
   sources = [
+    "audio_level.cc",
+    "audio_level.h",
     "audio_receive_stream.cc",
     "audio_receive_stream.h",
     "audio_send_stream.cc",
@@ -22,11 +24,19 @@
     "audio_state.h",
     "audio_transport_impl.cc",
     "audio_transport_impl.h",
+    "channel.cc",
+    "channel.h",
+    "channel_proxy.cc",
+    "channel_proxy.h",
     "conversion.h",
     "null_audio_poller.cc",
     "null_audio_poller.h",
+    "remix_resample.cc",
+    "remix_resample.h",
     "time_interval.cc",
     "time_interval.h",
+    "transport_feedback_packet_loss_tracker.cc",
+    "transport_feedback_packet_loss_tracker.h",
   ]
 
   if (!build_with_chromium && is_clang) {
@@ -36,15 +46,23 @@
 
   deps = [
     "..:webrtc_common",
+    "../api:array_view",
     "../api:audio_mixer_api",
     "../api:call_api",
+    "../api:libjingle_peerconnection_api",
     "../api:optional",
+    "../api:transport_api",
     "../api/audio_codecs:audio_codecs_api",
     "../api/audio_codecs:builtin_audio_encoder_factory",
     "../call:bitrate_allocator",
     "../call:call_interfaces",
     "../call:rtp_interfaces",
     "../common_audio",
+    "../logging:rtc_event_log_api",
+    "../modules:module_api",
+    "../modules/audio_coding",
+    "../modules/audio_coding:audio_format_conversion",
+    "../modules/audio_coding:audio_network_adaptor_config",
     "../modules/audio_coding:cng",
     "../modules/audio_device",
     "../modules/audio_processing",
@@ -53,14 +71,16 @@
     "../modules/pacing:pacing",
     "../modules/remote_bitrate_estimator:remote_bitrate_estimator",
     "../modules/rtp_rtcp",
+    "../modules/rtp_rtcp:rtp_rtcp_format",
+    "../modules/utility",
     "../rtc_base:checks",
+    "../rtc_base:rate_limiter",
     "../rtc_base:rtc_base",
     "../rtc_base:rtc_base_approved",
     "../rtc_base:rtc_task_queue",
     "../system_wrappers",
     "../system_wrappers:field_trial_api",
-    "../voice_engine",
-    "../voice_engine:audio_level",
+    "../system_wrappers:metrics_api",
     "utility:audio_frame_operations",
   ]
 }
@@ -94,7 +114,10 @@
       "audio_send_stream_tests.cc",
       "audio_send_stream_unittest.cc",
       "audio_state_unittest.cc",
+      "mock_voe_channel_proxy.h",
+      "remix_resample_unittest.cc",
       "time_interval_unittest.cc",
+      "transport_feedback_packet_loss_tracker_unittest.cc",
     ]
     deps = [
       ":audio",
@@ -104,7 +127,9 @@
       "../call:mock_rtp_interfaces",
       "../call:rtp_interfaces",
       "../call:rtp_receiver",
+      "../common_audio",
       "../logging:mocks",
+      "../modules:module_api",
       "../modules/audio_device:mock_audio_device",
       "../modules/audio_mixer:audio_mixer_impl",
       "../modules/audio_processing:audio_processing_statistics",
@@ -116,6 +141,7 @@
       "../modules/pacing:pacing",
       "../modules/rtp_rtcp:mock_rtp_rtcp",
       "../modules/rtp_rtcp:rtp_rtcp_format",
+      "../rtc_base:checks",
       "../rtc_base:rtc_base_approved",
       "../rtc_base:rtc_base_tests_utils",
       "../rtc_base:rtc_task_queue",
@@ -125,7 +151,6 @@
       "../test:rtp_test_utils",
       "../test:test_common",
       "../test:test_support",
-      "../voice_engine",
       "utility:utility_tests",
       "//testing/gmock",
       "//testing/gtest",