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

BUG=webrtc:5079

Review-Url: https://codereview.webrtc.org/2941253002
Cr-Commit-Position: refs/heads/master@{#18634}
diff --git a/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc b/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
index fb54dee..a012998 100644
--- a/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
+++ b/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
@@ -433,20 +433,20 @@
         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_);