Probing: Add support for exponential startup probing

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 152 matching lines @@
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
   EXPECT_EQ(300000, bitrate_observer_.last_bitrate_);
   time_ms += 1000;
 
   report_blocks.clear();
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 141));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
   EXPECT_EQ(300000, bitrate_observer_.last_bitrate_);
 
   // Test that a low delay-based estimate limits the combined estimate.
-  controller_->UpdateDelayBasedEstimate(280000);
+  controller_->OnReceiveBitrateChanged({0}, 280000);
   EXPECT_EQ(280000, bitrate_observer_.last_bitrate_);
 
   // Test that a low REMB limits the combined estimate.
   bandwidth_observer_->OnReceivedEstimatedBitrate(250000);
   EXPECT_EQ(250000, bitrate_observer_.last_bitrate_);
   EXPECT_EQ(0, bitrate_observer_.last_fraction_loss_);
   EXPECT_EQ(50, bitrate_observer_.last_rtt_);
 
   bandwidth_observer_->OnReceivedEstimatedBitrate(1000);
   EXPECT_EQ(100000, bitrate_observer_.last_bitrate_);
@@ skipping 215 matching lines @@
   EXPECT_EQ(120000, bitrate_observer_.last_bitrate_);
   controller_->SetReservedBitrate(50000);
   bandwidth_observer_->OnReceivedEstimatedBitrate(120000);
   // Limited by min bitrate.
   EXPECT_EQ(100000, bitrate_observer_.last_bitrate_);
 
   controller_->SetReservedBitrate(10000);
   bandwidth_observer_->OnReceivedEstimatedBitrate(1);
   EXPECT_EQ(100000, bitrate_observer_.last_bitrate_);
 }