Stop increasing loss-based BWE if no feedback is received.

webrtc/modules/bitrate_controller/send_side_bandwidth_estimation_unittest.cc

 /*
  *  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.
  */
 
@@ skipping 71 matching lines @@
   uint8_t fraction_loss;
   int64_t rtt_ms;
   bwe.CurrentEstimate(&bitrate_bps, &fraction_loss, &rtt_ms);
   EXPECT_EQ(kInitialBitrateBps, bitrate_bps);
   EXPECT_EQ(0, fraction_loss);
   EXPECT_EQ(0, rtt_ms);
 
   // Signal heavy loss to go down in bitrate.
   bwe.UpdateReceiverBlock(kFractionLoss, kRttMs, 100, now_ms);
   // Trigger an update 2 seconds later to not be rate limited.
-  now_ms += 2000;
+  now_ms += 1000;
   bwe.UpdateEstimate(now_ms);
 
   bwe.CurrentEstimate(&bitrate_bps, &fraction_loss, &rtt_ms);
   EXPECT_LT(bitrate_bps, kInitialBitrateBps);
   // Verify that the obtained bitrate isn't hitting the min bitrate, or this
   // test doesn't make sense. If this ever happens, update the thresholds or
   // loss rates so that it doesn't hit min bitrate after one bitrate update.
   EXPECT_GT(bitrate_bps, kMinBitrateBps);
   EXPECT_EQ(kFractionLoss, fraction_loss);
   EXPECT_EQ(kRttMs, rtt_ms);
 
   // Triggering an update shouldn't apply further downgrade nor upgrade since
   // there's no intermediate receiver block received indicating whether this is
   // currently good or not.
   int last_bitrate_bps = bitrate_bps;
   // Trigger an update 2 seconds later to not be rate limited (but it still
   // shouldn't update).
-  now_ms += 2000;
+  now_ms += 1000;
   bwe.UpdateEstimate(now_ms);
   bwe.CurrentEstimate(&bitrate_bps, &fraction_loss, &rtt_ms);
 
   EXPECT_EQ(last_bitrate_bps, bitrate_bps);
   // The old loss rate should still be applied though.
   EXPECT_EQ(kFractionLoss, fraction_loss);
   EXPECT_EQ(kRttMs, rtt_ms);
 }
 
 }  // namespace webrtc