Add a new overuse estimator for the delay based BWE behind experiment.

webrtc/modules/congestion_controller/BUILD.gn

 # Copyright (c) 2014 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("../../build/webrtc.gni")
 
 rtc_static_library("congestion_controller") {
   sources = [
     "congestion_controller.cc",
     "delay_based_bwe.cc",
     "delay_based_bwe.h",
     "include/congestion_controller.h",
     "probe_bitrate_estimator.cc",
     "probe_bitrate_estimator.h",
     "probe_controller.cc",
     "probe_controller.h",
     "transport_feedback_adapter.cc",
     "transport_feedback_adapter.h",
+    "trendline_estimator.cc",
+    "trendline_estimator.h",
   ]
 
+  if (rtc_enable_bwe_test_logging) {
+    defines = [ "BWE_TEST_LOGGING_COMPILE_TIME_ENABLE=1" ]
+  } else {
+    defines = [ "BWE_TEST_LOGGING_COMPILE_TIME_ENABLE=0" ]
+  }
+
   # TODO(jschuh): Bug 1348: fix this warning.
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 
   if (!build_with_chromium && is_clang) {
     # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
     suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
   }
 
   deps = [
     "../bitrate_controller",
     "../pacing",
   ]
 }