Made modules/audio_processing/vad its own target.

WHAT: made a BUILD.gn with library and tests in the Audio Processing
Module Voice Activity Detector directory. Updated depending
code. Fixed a Clang warning.

WHY: to make it possible for a target to depend on just the VAD and
not the whole APM. There are other benefits:

* Sometimes faster compilation.

* The VAD takes up 28000 bytes of libjingle_peerconnection_so.so. Making
  a peerconnection shared object file without the VAD has to be done in
  steps. The first step is a custom target for the VAD. Hence this Cl.

Change-Id: Iea0207a0b5979db26baaf46b24beaefbb1c431af
BUG: webrtc:5716, webrtc:7494
Reviewed-on: https://webrtc-review.googlesource.com/47521
Commit-Queue: Alex Loiko <aleloi@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21893}

modules/audio_processing/BUILD.gn

@@ -206,26 +206,6 @@ rtc_static_library("audio_processing") {
     "transient/wpd_tree.h",
     "typing_detection.cc",
     "typing_detection.h",
-    "vad/common.h",
-    "vad/gmm.cc",
-    "vad/gmm.h",
-    "vad/noise_gmm_tables.h",
-    "vad/pitch_based_vad.cc",
-    "vad/pitch_based_vad.h",
-    "vad/pitch_internal.cc",
-    "vad/pitch_internal.h",
-    "vad/pole_zero_filter.cc",
-    "vad/pole_zero_filter.h",
-    "vad/standalone_vad.cc",
-    "vad/standalone_vad.h",
-    "vad/vad_audio_proc.cc",
-    "vad/vad_audio_proc.h",
-    "vad/vad_audio_proc_internal.h",
-    "vad/vad_circular_buffer.cc",
-    "vad/vad_circular_buffer.h",
-    "vad/voice_activity_detector.cc",
-    "vad/voice_activity_detector.h",
-    "vad/voice_gmm_tables.h",
     "voice_detection_impl.cc",
     "voice_detection_impl.h",
   ]
@@ -251,7 +231,7 @@ rtc_static_library("audio_processing") {
     "../../system_wrappers:cpu_features_api",
     "../../system_wrappers:field_trial_api",
     "../../system_wrappers:metrics_api",
-    "../audio_coding:isac",
+    "vad",
   ]
 
   if (aec_untrusted_delay_for_testing) {
@@ -573,14 +553,6 @@ if (rtc_include_tests) {
       "transient/wpd_tree_unittest.cc",
       "utility/block_mean_calculator_unittest.cc",
       "utility/delay_estimator_unittest.cc",
-      "vad/gmm_unittest.cc",
-      "vad/pitch_based_vad_unittest.cc",
-      "vad/pitch_internal_unittest.cc",
-      "vad/pole_zero_filter_unittest.cc",
-      "vad/standalone_vad_unittest.cc",
-      "vad/vad_audio_proc_unittest.cc",
-      "vad/vad_circular_buffer_unittest.cc",
-      "vad/voice_activity_detector_unittest.cc",
     ]
 
     deps = [
@@ -607,6 +579,7 @@ if (rtc_include_tests) {
       "../audio_coding:neteq_input_audio_tools",
       "aec_dump:mock_aec_dump_unittests",
       "test/conversational_speech:unittest",
+      "vad:vad_unittests",
       "//testing/gtest",
     ]
 
@@ -876,6 +849,7 @@ if (rtc_include_tests) {
       deps = [
         ":audio_processing",
         ":audioproc_test_utils",
+        "../../common_audio",
         "../../rtc_base:rtc_base_approved",
         "../../system_wrappers:metrics_default",
         "../../test:test_support",

modules/audio_processing/test/py_quality_assessment/BUILD.gn

@@ -143,6 +143,7 @@ rtc_executable("apm_vad") {
     "../../../../common_audio",
     "../../../../rtc_base:rtc_base_approved",
     "../../../../system_wrappers:metrics_default",
+    "../../vad",
   ]
 }
 

modules/audio_processing/vad/BUILD.gn

@@ -0,0 +1,69 @@
+# Copyright (c) 2018 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.
+
+import("../../../webrtc.gni")
+rtc_static_library("vad") {
+  visibility = [
+    "../*",
+    "../../../rtc_tools:*",
+  ]
+  sources = [
+    "common.h",
+    "gmm.cc",
+    "gmm.h",
+    "noise_gmm_tables.h",
+    "pitch_based_vad.cc",
+    "pitch_based_vad.h",
+    "pitch_internal.cc",
+    "pitch_internal.h",
+    "pole_zero_filter.cc",
+    "pole_zero_filter.h",
+    "standalone_vad.cc",
+    "standalone_vad.h",
+    "vad_audio_proc.cc",
+    "vad_audio_proc.h",
+    "vad_audio_proc_internal.h",
+    "vad_circular_buffer.cc",
+    "vad_circular_buffer.h",
+    "voice_activity_detector.cc",
+    "voice_activity_detector.h",
+    "voice_gmm_tables.h",
+  ]
+  deps = [
+    "../..:module_api",
+    "../../..:typedefs",
+    "../../../audio/utility:audio_frame_operations",
+    "../../../common_audio",
+    "../../../rtc_base:checks",
+    "../../audio_coding:isac",
+  ]
+}
+
+if (rtc_include_tests) {
+  rtc_static_library("vad_unittests") {
+    testonly = true
+    sources = [
+      "gmm_unittest.cc",
+      "pitch_based_vad_unittest.cc",
+      "pitch_internal_unittest.cc",
+      "pole_zero_filter_unittest.cc",
+      "standalone_vad_unittest.cc",
+      "vad_audio_proc_unittest.cc",
+      "vad_circular_buffer_unittest.cc",
+      "voice_activity_detector_unittest.cc",
+    ]
+    deps = [
+      ":vad",
+      "../..:module_api",
+      "../../../common_audio",
+      "../../../test:test_support",
+      "//testing/gmock",
+      "//testing/gtest",
+    ]
+  }
+}

modules/audio_processing/vad/pole_zero_filter_unittest.cc

@@ -53,7 +53,7 @@ class PoleZeroFilterTest : public ::testing::Test {
                                           kCoeffDenominator,
                                           kFilterOrder)) {}
 
-  ~PoleZeroFilterTest() {}
+  ~PoleZeroFilterTest() override {}
 
   void FilterSubframes(int num_subframes);
 

rtc_tools/BUILD.gn

@@ -289,6 +289,7 @@ if (rtc_include_tests) {
     deps = [
       "../modules:module_api",
       "../modules/audio_processing",
+      "../modules/audio_processing/vad",
       "../rtc_base:rtc_base_approved",
       "../system_wrappers:metrics_default",
       "../test:test_support",