Tune loss-based BWE to be more compatible with the low frequency loss reports of audio streams.

webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc

 /*
  *  Copyright (c) 2012 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.
  */
 
@@ skipping 415 matching lines @@
     report_blocks.clear();
     expected_bitrate_bps = expected_bitrate_bps * 1.08 + 1000;
     EXPECT_EQ(expected_bitrate_bps, bitrate_observer_.last_bitrate_);
     clock_.AdvanceTimeMilliseconds(1500);
 
     report_blocks.push_back(CreateReportBlock(1, 2, 0, 41));
     bandwidth_observer_->OnReceivedRtcpReceiverReport(
         report_blocks, 50, clock_.TimeInMilliseconds());
     expected_bitrate_bps = expected_bitrate_bps * 1.08 + 1000;
     EXPECT_EQ(expected_bitrate_bps, bitrate_observer_.last_bitrate_);
-    clock_.AdvanceTimeMilliseconds(1000);
+    clock_.AdvanceTimeMilliseconds(4000);
 
-    // 1 seconds since feedback, expect increase.
+    // 4 seconds since feedback, expect increase.
     controller_->Process();
     expected_bitrate_bps = expected_bitrate_bps * 1.08 + 1000;
     EXPECT_EQ(expected_bitrate_bps, bitrate_observer_.last_bitrate_);
-    clock_.AdvanceTimeMilliseconds(800);
+    clock_.AdvanceTimeMilliseconds(2000);
 
-    // 1.8 seconds since feedback, expect no increase.
+    // 6 seconds since feedback, expect no increase.
     controller_->Process();
     EXPECT_EQ(expected_bitrate_bps, bitrate_observer_.last_bitrate_);
-    clock_.AdvanceTimeMilliseconds(3701);
+    clock_.AdvanceTimeMilliseconds(9001);
 
-    // More than 4.5 seconds since feedback, expect decrease.
+    // More than 15 seconds since feedback, expect decrease.
     controller_->Process();
     expected_bitrate_bps *= 0.8;
     EXPECT_EQ(expected_bitrate_bps, bitrate_observer_.last_bitrate_);
     clock_.AdvanceTimeMilliseconds(500);
 
     // Only one timeout every second.
     controller_->Process();
     EXPECT_EQ(expected_bitrate_bps, bitrate_observer_.last_bitrate_);
     clock_.AdvanceTimeMilliseconds(501);
 
@@ skipping 40 matching lines @@
   clock_.AdvanceTimeMilliseconds(100);
 
   // 15 packets reported as received since last, enough to increase.
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 41));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(
       report_blocks, 50, clock_.TimeInMilliseconds());
   expected_bitrate_bps = expected_bitrate_bps * 1.08 + 1000;
   EXPECT_EQ(expected_bitrate_bps, bitrate_observer_.last_bitrate_);
   clock_.AdvanceTimeMilliseconds(1000);
 }