AecDump implementation.

webrtc/modules/audio_processing/aec_dump/BUILD.gn

 # Copyright (c) 2017 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")
+import("../../../webrtc.gni")  # This contains def of 'rtc_enable_protobuf'
 
 rtc_source_set("aec_dump") {
   sources = [
-    "aec_dump.cc",
     "aec_dump.h",
   ]
 
+  public = [
+    "aec_dump.h",
+  ]
+
   deps = [
     "../../../base:rtc_base_approved",
     "../../../modules:module_api",
     "../../../system_wrappers",
   ]
+
+  if (rtc_enable_protobuf) {
+    sources += [
+      "aec_dump.cc",
+      "capture_stream_info_impl.cc",
+      "write_to_file_task.cc",
+      "write_to_file_task.h",
+    ]
+    deps += [
+      "../:audioproc_debug_proto",
+      "../../../base:protobuf_utils",
+      "../../../base:rtc_task_queue",
+    ]
+  } else {
+    sources += [ "aec_dump_no_protobuf.cc" ]
+  }
 }
+
+if (rtc_enable_protobuf) {
+  rtc_source_set("aec_dump_unittests") {
+    testonly = true
+    defines = []
+    deps = [
+      ":aec_dump",
+      "..:audioproc_debug_proto",
+      "../../../base:rtc_task_queue",
+      "../../../modules:module_api",
+      "../../../test:test_support",
+      "//testing/gtest",
+    ]
+    sources = [
+      "aec_dump_unittest.cc",
+    ]
+  }
+}