Break out allocation from BitrateController into a BitrateAllocator.

This also refactors some of the padding and allocation code in ViEEncoder, and
makes ChannelGroup a simple forwarder from BitrateController to
BitrateAllocator.

This CL is part of a bigger picture, see https://review.webrtc.org/35319004/ for
details.

BUG=4323
R=mflodman@webrtc.org, pbos@webrtc.org, sprang@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/44399004

Cr-Commit-Position: refs/heads/master@{#8595}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8595 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc b/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
index f89da9f..e8d49c6 100644
--- a/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
+++ b/webrtc/modules/bitrate_controller/bitrate_controller_unittest.cc
@@ -57,12 +57,14 @@
 
 class BitrateControllerTest : public ::testing::Test {
  protected:
-  BitrateControllerTest() : clock_(0), enforce_min_bitrate_(true) {}
+  BitrateControllerTest() : clock_(0) {}
   ~BitrateControllerTest() {}
 
   virtual void SetUp() {
-    controller_ = BitrateController::CreateBitrateController(
-        &clock_, enforce_min_bitrate_);
+    controller_ =
+        BitrateController::CreateBitrateController(&clock_, &bitrate_observer_);
+    controller_->SetStartBitrate(200000);
+    controller_->SetMinMaxBitrate(100000, 300000);
     bandwidth_observer_ = controller_->CreateRtcpBandwidthObserver();
   }
 
@@ -72,47 +74,20 @@
   }
 
   webrtc::SimulatedClock clock_;
-  bool enforce_min_bitrate_;
+  TestBitrateObserver bitrate_observer_;
   BitrateController* controller_;
   RtcpBandwidthObserver* bandwidth_observer_;
 };
 
-TEST_F(BitrateControllerTest, Basic) {
-  TestBitrateObserver bitrate_observer;
-  controller_->SetBitrateObserver(&bitrate_observer, 200000, 100000, 300000);
-  controller_->RemoveBitrateObserver(&bitrate_observer);
-}
-
-TEST_F(BitrateControllerTest, UpdatingBitrateObserver) {
-  TestBitrateObserver bitrate_observer;
-  controller_->SetBitrateObserver(&bitrate_observer, 200000, 100000, 1500000);
-  clock_.AdvanceTimeMilliseconds(25);
-  controller_->Process();
-  EXPECT_EQ(200000u, bitrate_observer.last_bitrate_);
-
-  controller_->SetBitrateObserver(&bitrate_observer, 1500000, 100000, 1500000);
-  clock_.AdvanceTimeMilliseconds(25);
-  controller_->Process();
-  EXPECT_EQ(1500000u, bitrate_observer.last_bitrate_);
-
-  controller_->SetBitrateObserver(&bitrate_observer, 500000, 100000, 1500000);
-  clock_.AdvanceTimeMilliseconds(25);
-  controller_->Process();
-  EXPECT_EQ(1500000u, bitrate_observer.last_bitrate_);
-}
-
 TEST_F(BitrateControllerTest, OneBitrateObserverOneRtcpObserver) {
-  TestBitrateObserver bitrate_observer;
-  controller_->SetBitrateObserver(&bitrate_observer, 200000, 100000, 300000);
-
   // First REMB applies immediately.
   int64_t time_ms = 1001;
   webrtc::ReportBlockList report_blocks;
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 1));
   bandwidth_observer_->OnReceivedEstimatedBitrate(200000);
-  EXPECT_EQ(200000u, bitrate_observer.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer.last_fraction_loss_);
-  EXPECT_EQ(0, bitrate_observer.last_rtt_);
+  EXPECT_EQ(200000u, bitrate_observer_.last_bitrate_);
+  EXPECT_EQ(0, bitrate_observer_.last_fraction_loss_);
+  EXPECT_EQ(0, bitrate_observer_.last_rtt_);
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
   report_blocks.clear();
   time_ms += 2000;
@@ -123,64 +98,60 @@
   // Test bitrate increase 8% per second.
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 21));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(217000u, bitrate_observer.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer.last_fraction_loss_);
-  EXPECT_EQ(50, bitrate_observer.last_rtt_);
+  EXPECT_EQ(217000u, bitrate_observer_.last_bitrate_);
+  EXPECT_EQ(0, bitrate_observer_.last_fraction_loss_);
+  EXPECT_EQ(50, bitrate_observer_.last_rtt_);
   time_ms += 1000;
 
   report_blocks.clear();
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 41));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(235360u, bitrate_observer.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer.last_fraction_loss_);
-  EXPECT_EQ(50, bitrate_observer.last_rtt_);
+  EXPECT_EQ(235360u, bitrate_observer_.last_bitrate_);
+  EXPECT_EQ(0, bitrate_observer_.last_fraction_loss_);
+  EXPECT_EQ(50, bitrate_observer_.last_rtt_);
   time_ms += 1000;
 
   report_blocks.clear();
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 61));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(255189u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(255189u, bitrate_observer_.last_bitrate_);
   time_ms += 1000;
 
   report_blocks.clear();
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 81));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(276604u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(276604u, bitrate_observer_.last_bitrate_);
   time_ms += 1000;
 
   report_blocks.clear();
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 801));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(299732u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(299732u, bitrate_observer_.last_bitrate_);
   time_ms += 1000;
 
   // Reach max cap.
   report_blocks.clear();
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 101));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(300000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(300000u, 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(300000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(300000u, bitrate_observer_.last_bitrate_);
 
   // Test that a low REMB trigger immediately.
   bandwidth_observer_->OnReceivedEstimatedBitrate(250000);
-  EXPECT_EQ(250000u, bitrate_observer.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer.last_fraction_loss_);
-  EXPECT_EQ(50, bitrate_observer.last_rtt_);
+  EXPECT_EQ(250000u, 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(100000u, bitrate_observer.last_bitrate_);  // Min cap.
-  controller_->RemoveBitrateObserver(&bitrate_observer);
+  EXPECT_EQ(100000u, bitrate_observer_.last_bitrate_);  // Min cap.
 }
 
 TEST_F(BitrateControllerTest, OneBitrateObserverTwoRtcpObservers) {
-  TestBitrateObserver bitrate_observer;
-  controller_->SetBitrateObserver(&bitrate_observer, 200000, 100000, 300000);
-
   // REMBs during the first 2 seconds apply immediately.
   int64_t time_ms = 1;
   webrtc::ReportBlockList report_blocks;
@@ -196,9 +167,9 @@
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 21));
   second_bandwidth_observer->OnReceivedRtcpReceiverReport(
       report_blocks, 100, 1);
-  EXPECT_EQ(217000u, bitrate_observer.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer.last_fraction_loss_);
-  EXPECT_EQ(100, bitrate_observer.last_rtt_);
+  EXPECT_EQ(217000u, bitrate_observer_.last_bitrate_);
+  EXPECT_EQ(0, bitrate_observer_.last_fraction_loss_);
+  EXPECT_EQ(100, bitrate_observer_.last_rtt_);
   time_ms += 500;
 
   // Test bitrate increase 8% per second.
@@ -208,9 +179,9 @@
   time_ms += 500;
   second_bandwidth_observer->OnReceivedRtcpReceiverReport(
       report_blocks, 100, time_ms);
-  EXPECT_EQ(235360u, bitrate_observer.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer.last_fraction_loss_);
-  EXPECT_EQ(100, bitrate_observer.last_rtt_);
+  EXPECT_EQ(235360u, bitrate_observer_.last_bitrate_);
+  EXPECT_EQ(0, bitrate_observer_.last_fraction_loss_);
+  EXPECT_EQ(100, bitrate_observer_.last_rtt_);
   time_ms += 500;
 
   // Extra report should not change estimate.
@@ -218,20 +189,20 @@
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 31));
   second_bandwidth_observer->OnReceivedRtcpReceiverReport(
       report_blocks, 100, time_ms);
-  EXPECT_EQ(235360u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(235360u, bitrate_observer_.last_bitrate_);
   time_ms += 500;
 
   report_blocks.clear();
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 41));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(255189u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(255189u, bitrate_observer_.last_bitrate_);
 
   // Second report should not change estimate.
   report_blocks.clear();
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 41));
   second_bandwidth_observer->OnReceivedRtcpReceiverReport(
       report_blocks, 100, time_ms);
-  EXPECT_EQ(255189u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(255189u, bitrate_observer_.last_bitrate_);
   time_ms += 1000;
 
   // Reports from only one bandwidth observer is ok.
@@ -239,14 +210,14 @@
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 61));
   second_bandwidth_observer->OnReceivedRtcpReceiverReport(
       report_blocks, 50, time_ms);
-  EXPECT_EQ(276604u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(276604u, bitrate_observer_.last_bitrate_);
   time_ms += 1000;
 
   report_blocks.clear();
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 81));
   second_bandwidth_observer->OnReceivedRtcpReceiverReport(
       report_blocks, 50, time_ms);
-  EXPECT_EQ(299732u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(299732u, bitrate_observer_.last_bitrate_);
   time_ms += 1000;
 
   // Reach max cap.
@@ -254,37 +225,35 @@
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 121));
   second_bandwidth_observer->OnReceivedRtcpReceiverReport(
       report_blocks, 50, time_ms);
-  EXPECT_EQ(300000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(300000u, bitrate_observer_.last_bitrate_);
   time_ms += 1000;
 
   report_blocks.clear();
   report_blocks.push_back(CreateReportBlock(1, 2, 0, 141));
   second_bandwidth_observer->OnReceivedRtcpReceiverReport(
       report_blocks, 50, time_ms);
-  EXPECT_EQ(300000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(300000u, bitrate_observer_.last_bitrate_);
 
   // Test that a low REMB trigger immediately.
   // We don't care which bandwidth observer that delivers the REMB.
   second_bandwidth_observer->OnReceivedEstimatedBitrate(250000);
-  EXPECT_EQ(250000u, bitrate_observer.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer.last_fraction_loss_);
-  EXPECT_EQ(50, bitrate_observer.last_rtt_);
+  EXPECT_EQ(250000u, bitrate_observer_.last_bitrate_);
+  EXPECT_EQ(0, bitrate_observer_.last_fraction_loss_);
+  EXPECT_EQ(50, bitrate_observer_.last_rtt_);
 
   // Min cap.
   bandwidth_observer_->OnReceivedEstimatedBitrate(1000);
-  EXPECT_EQ(100000u, bitrate_observer.last_bitrate_);
-  controller_->RemoveBitrateObserver(&bitrate_observer);
+  EXPECT_EQ(100000u, bitrate_observer_.last_bitrate_);
   delete second_bandwidth_observer;
 }
 
 TEST_F(BitrateControllerTest, OneBitrateObserverMultipleReportBlocks) {
-  TestBitrateObserver bitrate_observer;
   uint32_t sequence_number[2] = {0, 0xFF00};
   const uint32_t kStartBitrate = 200000;
   const uint32_t kMinBitrate = 100000;
   const uint32_t kMaxBitrate = 300000;
-  controller_->SetBitrateObserver(&bitrate_observer, kStartBitrate, kMinBitrate,
-                                  kMaxBitrate);
+  controller_->SetStartBitrate(kStartBitrate);
+  controller_->SetMinMaxBitrate(kMinBitrate, kMaxBitrate);
 
   // REMBs during the first 2 seconds apply immediately.
   int64_t time_ms = 1001;
@@ -305,26 +274,26 @@
     report_blocks.push_back(CreateReportBlock(1, 3, 0, sequence_number[1]));
     bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50,
                                                       time_ms);
-    EXPECT_GT(bitrate_observer.last_bitrate_, last_bitrate);
-    EXPECT_EQ(0, bitrate_observer.last_fraction_loss_);
-    EXPECT_EQ(50, bitrate_observer.last_rtt_);
-    last_bitrate = bitrate_observer.last_bitrate_;
+    EXPECT_GT(bitrate_observer_.last_bitrate_, last_bitrate);
+    EXPECT_EQ(0, bitrate_observer_.last_fraction_loss_);
+    EXPECT_EQ(50, bitrate_observer_.last_rtt_);
+    last_bitrate = bitrate_observer_.last_bitrate_;
     time_ms += 1000;
     sequence_number[0] += 20;
     sequence_number[1] += 1;
     report_blocks.clear();
   }
 
-  EXPECT_EQ(kMaxBitrate, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(kMaxBitrate, bitrate_observer_.last_bitrate_);
 
   // Packet loss on the first stream. Verify that bitrate decreases.
   report_blocks.push_back(CreateReportBlock(1, 2, 50, sequence_number[0]));
   report_blocks.push_back(CreateReportBlock(1, 3, 0, sequence_number[1]));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_LT(bitrate_observer.last_bitrate_, last_bitrate);
-  EXPECT_EQ(WeightedLoss(20, 50, 1, 0), bitrate_observer.last_fraction_loss_);
-  EXPECT_EQ(50, bitrate_observer.last_rtt_);
-  last_bitrate = bitrate_observer.last_bitrate_;
+  EXPECT_LT(bitrate_observer_.last_bitrate_, last_bitrate);
+  EXPECT_EQ(WeightedLoss(20, 50, 1, 0), bitrate_observer_.last_fraction_loss_);
+  EXPECT_EQ(50, bitrate_observer_.last_rtt_);
+  last_bitrate = bitrate_observer_.last_bitrate_;
   sequence_number[0] += 20;
   sequence_number[1] += 20;
   time_ms += 1000;
@@ -334,10 +303,10 @@
   report_blocks.push_back(CreateReportBlock(1, 2, 0, sequence_number[0]));
   report_blocks.push_back(CreateReportBlock(1, 3, 75, sequence_number[1]));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_LT(bitrate_observer.last_bitrate_, last_bitrate);
-  EXPECT_EQ(WeightedLoss(20, 0, 20, 75), bitrate_observer.last_fraction_loss_);
-  EXPECT_EQ(50, bitrate_observer.last_rtt_);
-  last_bitrate = bitrate_observer.last_bitrate_;
+  EXPECT_LT(bitrate_observer_.last_bitrate_, last_bitrate);
+  EXPECT_EQ(WeightedLoss(20, 0, 20, 75), bitrate_observer_.last_fraction_loss_);
+  EXPECT_EQ(50, bitrate_observer_.last_rtt_);
+  last_bitrate = bitrate_observer_.last_bitrate_;
   sequence_number[0] += 20;
   sequence_number[1] += 1;
   time_ms += 1000;
@@ -347,295 +316,61 @@
   report_blocks.push_back(CreateReportBlock(1, 2, 1, sequence_number[0]));
   report_blocks.push_back(CreateReportBlock(1, 3, 255, sequence_number[1]));
   bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(bitrate_observer.last_bitrate_, last_bitrate);
-  EXPECT_EQ(WeightedLoss(20, 1, 1, 255), bitrate_observer.last_fraction_loss_);
-  EXPECT_EQ(50, bitrate_observer.last_rtt_);
-  last_bitrate = bitrate_observer.last_bitrate_;
+  EXPECT_EQ(bitrate_observer_.last_bitrate_, last_bitrate);
+  EXPECT_EQ(WeightedLoss(20, 1, 1, 255), bitrate_observer_.last_fraction_loss_);
+  EXPECT_EQ(50, bitrate_observer_.last_rtt_);
+  last_bitrate = bitrate_observer_.last_bitrate_;
   sequence_number[0] += 20;
   sequence_number[1] += 1;
   report_blocks.clear();
 }
 
-TEST_F(BitrateControllerTest, TwoBitrateObserversOneRtcpObserver) {
-  TestBitrateObserver bitrate_observer_1;
-  TestBitrateObserver bitrate_observer_2;
-  controller_->SetBitrateObserver(&bitrate_observer_2, 200000, 200000, 300000);
-  controller_->SetBitrateObserver(&bitrate_observer_1, 200000, 100000, 300000);
-
-  // REMBs during the first 2 seconds apply immediately.
-  int64_t time_ms = 1001;
-  webrtc::ReportBlockList report_blocks;
-  report_blocks.push_back(CreateReportBlock(1, 2, 0, 1));
-  bandwidth_observer_->OnReceivedEstimatedBitrate(200000);
-  EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer_1.last_fraction_loss_);
-  EXPECT_EQ(0, bitrate_observer_1.last_rtt_);
-  bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  report_blocks.clear();
-  time_ms += 2000;
-
-  // Receive a high remb, test bitrate inc.
-  // Test too low start bitrate, hence lower than sum of min.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(400000);
-
-  // Test bitrate increase 8% per second, distributed equally.
-  report_blocks.push_back(CreateReportBlock(1, 2, 0, 21));
-  bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(112500u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer_1.last_fraction_loss_);
-  EXPECT_EQ(50, bitrate_observer_1.last_rtt_);
-  time_ms += 1000;
-
-  EXPECT_EQ(212500u, bitrate_observer_2.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer_2.last_fraction_loss_);
-  EXPECT_EQ(50, bitrate_observer_2.last_rtt_);
-
-  report_blocks.clear();
-  report_blocks.push_back(CreateReportBlock(1, 2, 0, 41));
-  bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(126000u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(226000u, bitrate_observer_2.last_bitrate_);
-  time_ms += 1000;
-
-  report_blocks.clear();
-  report_blocks.push_back(CreateReportBlock(1, 2, 0, 61));
-  bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(140580u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(240580u, bitrate_observer_2.last_bitrate_);
-  time_ms += 1000;
-
-  // Check that the bitrate sum honor our REMB.
-  report_blocks.clear();
-  report_blocks.push_back(CreateReportBlock(1, 2, 0, 101));
-  bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(150000u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(250000u, bitrate_observer_2.last_bitrate_);
-  time_ms += 1000;
-
-  // Remove REMB cap, higher than sum of max.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(700000);
-
-  report_blocks.clear();
-  report_blocks.push_back(CreateReportBlock(1, 2, 0, 121));
-  bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(166500u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(266500u, bitrate_observer_2.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(184320u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(284320u, bitrate_observer_2.last_bitrate_);
-  time_ms += 1000;
-
-  report_blocks.clear();
-  report_blocks.push_back(CreateReportBlock(1, 2, 0, 161));
-  bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(207130u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(300000u, bitrate_observer_2.last_bitrate_);  // Max cap.
-  time_ms += 1000;
-
-  report_blocks.clear();
-  report_blocks.push_back(CreateReportBlock(1, 2, 0, 181));
-  bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(248700u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(300000u, bitrate_observer_2.last_bitrate_);
-  time_ms += 1000;
-
-  report_blocks.clear();
-  report_blocks.push_back(CreateReportBlock(1, 2, 0, 201));
-  bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(293596u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(300000u, bitrate_observer_2.last_bitrate_);
-  time_ms += 1000;
-
-  report_blocks.clear();
-  report_blocks.push_back(CreateReportBlock(1, 2, 0, 221));
-  bandwidth_observer_->OnReceivedRtcpReceiverReport(report_blocks, 50, time_ms);
-  EXPECT_EQ(300000u, bitrate_observer_1.last_bitrate_);  // Max cap.
-  EXPECT_EQ(300000u, bitrate_observer_2.last_bitrate_);
-
-  // Test that a low REMB trigger immediately.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(350000);
-  EXPECT_EQ(125000u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer_1.last_fraction_loss_);
-  EXPECT_EQ(50, bitrate_observer_1.last_rtt_);
-  EXPECT_EQ(225000u, bitrate_observer_2.last_bitrate_);
-  EXPECT_EQ(0, bitrate_observer_2.last_fraction_loss_);
-  EXPECT_EQ(50, bitrate_observer_2.last_rtt_);
-
-  bandwidth_observer_->OnReceivedEstimatedBitrate(1000);
-  EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_);  // Min cap.
-  EXPECT_EQ(200000u, bitrate_observer_2.last_bitrate_);  // Min cap.
-  controller_->RemoveBitrateObserver(&bitrate_observer_1);
-  controller_->RemoveBitrateObserver(&bitrate_observer_2);
-}
-
 TEST_F(BitrateControllerTest, SetReservedBitrate) {
-  TestBitrateObserver bitrate_observer;
-  controller_->SetBitrateObserver(&bitrate_observer, 200000, 100000, 300000);
-
   // Receive successively lower REMBs, verify the reserved bitrate is deducted.
-
   controller_->SetReservedBitrate(0);
   bandwidth_observer_->OnReceivedEstimatedBitrate(400000);
-  EXPECT_EQ(200000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(200000u, bitrate_observer_.last_bitrate_);
   controller_->SetReservedBitrate(50000);
   bandwidth_observer_->OnReceivedEstimatedBitrate(400000);
-  EXPECT_EQ(150000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(150000u, bitrate_observer_.last_bitrate_);
 
   controller_->SetReservedBitrate(0);
   bandwidth_observer_->OnReceivedEstimatedBitrate(250000);
-  EXPECT_EQ(200000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(200000u, bitrate_observer_.last_bitrate_);
   controller_->SetReservedBitrate(50000);
   bandwidth_observer_->OnReceivedEstimatedBitrate(250000);
-  EXPECT_EQ(150000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(150000u, bitrate_observer_.last_bitrate_);
 
   controller_->SetReservedBitrate(0);
   bandwidth_observer_->OnReceivedEstimatedBitrate(200000);
-  EXPECT_EQ(200000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(200000u, bitrate_observer_.last_bitrate_);
   controller_->SetReservedBitrate(30000);
   bandwidth_observer_->OnReceivedEstimatedBitrate(200000);
-  EXPECT_EQ(170000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(170000u, bitrate_observer_.last_bitrate_);
 
   controller_->SetReservedBitrate(0);
   bandwidth_observer_->OnReceivedEstimatedBitrate(160000);
-  EXPECT_EQ(160000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(160000u, bitrate_observer_.last_bitrate_);
   controller_->SetReservedBitrate(30000);
   bandwidth_observer_->OnReceivedEstimatedBitrate(160000);
-  EXPECT_EQ(130000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(130000u, bitrate_observer_.last_bitrate_);
 
   controller_->SetReservedBitrate(0);
   bandwidth_observer_->OnReceivedEstimatedBitrate(120000);
-  EXPECT_EQ(120000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(120000u, bitrate_observer_.last_bitrate_);
   controller_->SetReservedBitrate(10000);
   bandwidth_observer_->OnReceivedEstimatedBitrate(120000);
-  EXPECT_EQ(110000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(110000u, bitrate_observer_.last_bitrate_);
 
   controller_->SetReservedBitrate(0);
   bandwidth_observer_->OnReceivedEstimatedBitrate(120000);
-  EXPECT_EQ(120000u, bitrate_observer.last_bitrate_);
+  EXPECT_EQ(120000u, bitrate_observer_.last_bitrate_);
   controller_->SetReservedBitrate(50000);
   bandwidth_observer_->OnReceivedEstimatedBitrate(120000);
-  EXPECT_EQ(100000u, bitrate_observer.last_bitrate_);
+  // Limited by min bitrate.
+  EXPECT_EQ(100000u, bitrate_observer_.last_bitrate_);
 
   controller_->SetReservedBitrate(10000);
-  bandwidth_observer_->OnReceivedEstimatedBitrate(0);
-  EXPECT_EQ(100000u, bitrate_observer.last_bitrate_);
-
-  controller_->RemoveBitrateObserver(&bitrate_observer);
-}
-
-class BitrateControllerTestNoEnforceMin : public BitrateControllerTest {
- protected:
-  BitrateControllerTestNoEnforceMin() : BitrateControllerTest() {
-    enforce_min_bitrate_ = false;
-  }
-};
-
-// The following three tests verify that the EnforceMinBitrate() method works
-// as intended.
-TEST_F(BitrateControllerTestNoEnforceMin, OneBitrateObserver) {
-  TestBitrateObserver bitrate_observer_1;
-  controller_->SetBitrateObserver(&bitrate_observer_1, 200000, 100000, 400000);
-
-  // High REMB.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(150000);
-  EXPECT_EQ(150000u, bitrate_observer_1.last_bitrate_);
-
-  // Low REMB.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(10000);
-  EXPECT_EQ(10000u, bitrate_observer_1.last_bitrate_);
-
-  // Keeps at least 10 kbps.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(9000);
-  EXPECT_EQ(10000u, bitrate_observer_1.last_bitrate_);
-
-  controller_->RemoveBitrateObserver(&bitrate_observer_1);
-}
-
-TEST_F(BitrateControllerTestNoEnforceMin, SetReservedBitrate) {
-  TestBitrateObserver bitrate_observer_1;
-  controller_->SetBitrateObserver(&bitrate_observer_1, 200000, 100000, 400000);
-  controller_->SetReservedBitrate(10000);
-
-  // High REMB.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(150000);
-  EXPECT_EQ(140000u, bitrate_observer_1.last_bitrate_);
-
-  // Low REMB.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(15000);
-  EXPECT_EQ(5000u, bitrate_observer_1.last_bitrate_);
-
-  // Keeps at least 10 kbps.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(9000);
-  EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_);
-
-  controller_->RemoveBitrateObserver(&bitrate_observer_1);
-}
-
-TEST_F(BitrateControllerTestNoEnforceMin, ThreeBitrateObservers) {
-  TestBitrateObserver bitrate_observer_1;
-  TestBitrateObserver bitrate_observer_2;
-  TestBitrateObserver bitrate_observer_3;
-  // Set up the observers with min bitrates at 100000, 200000, and 300000.
-  // Note: The start bitrate of bitrate_observer_1 (700000) is used as the
-  // overall start bitrate.
-  controller_->SetBitrateObserver(&bitrate_observer_1, 700000, 100000, 400000);
-  controller_->SetBitrateObserver(&bitrate_observer_2, 200000, 200000, 400000);
-  controller_->SetBitrateObserver(&bitrate_observer_3, 200000, 300000, 400000);
-
-  // High REMB. Make sure the controllers get a fair share of the surplus
-  // (i.e., what is left after each controller gets its min rate).
-  bandwidth_observer_->OnReceivedEstimatedBitrate(690000);
-  // Verify that each observer gets its min rate (sum of min rates is 600000),
-  // and that the remaining 90000 is divided equally among the three.
-  EXPECT_EQ(130000u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(230000u, bitrate_observer_2.last_bitrate_);
-  EXPECT_EQ(330000u, bitrate_observer_3.last_bitrate_);
-
-  // High REMB, but below the sum of min bitrates.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(500000);
-  // Verify that the first and second observers get their min bitrates, and the
-  // third gets the remainder.
-  EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_);  // Min bitrate.
-  EXPECT_EQ(200000u, bitrate_observer_2.last_bitrate_);  // Min bitrate.
-  EXPECT_EQ(200000u, bitrate_observer_3.last_bitrate_);  // Remainder.
-
-  // Low REMB.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(10000);
-  // Verify that the first observer gets all the rate, and the rest get zero.
-  EXPECT_EQ(10000u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(0u, bitrate_observer_2.last_bitrate_);
-  EXPECT_EQ(0u, bitrate_observer_3.last_bitrate_);
-
-  // Verify it keeps an estimate of at least 10kbps.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(9000);
-  EXPECT_EQ(10000u, bitrate_observer_1.last_bitrate_);
-  EXPECT_EQ(0u, bitrate_observer_2.last_bitrate_);
-  EXPECT_EQ(0u, bitrate_observer_3.last_bitrate_);
-
-  controller_->RemoveBitrateObserver(&bitrate_observer_1);
-  controller_->RemoveBitrateObserver(&bitrate_observer_2);
-  controller_->RemoveBitrateObserver(&bitrate_observer_3);
-}
-
-TEST_F(BitrateControllerTest, ThreeBitrateObserversLowRembEnforceMin) {
-  TestBitrateObserver bitrate_observer_1;
-  TestBitrateObserver bitrate_observer_2;
-  TestBitrateObserver bitrate_observer_3;
-  controller_->SetBitrateObserver(&bitrate_observer_1, 200000, 100000, 300000);
-  controller_->SetBitrateObserver(&bitrate_observer_2, 200000, 200000, 300000);
-  controller_->SetBitrateObserver(&bitrate_observer_3, 200000, 300000, 300000);
-
-  // Low REMB. Verify that all observers still get their respective min bitrate.
-  bandwidth_observer_->OnReceivedEstimatedBitrate(1000);
-  EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_);  // Min cap.
-  EXPECT_EQ(200000u, bitrate_observer_2.last_bitrate_);  // Min cap.
-  EXPECT_EQ(300000u, bitrate_observer_3.last_bitrate_);  // Min cap.
-
-  controller_->RemoveBitrateObserver(&bitrate_observer_1);
-  controller_->RemoveBitrateObserver(&bitrate_observer_2);
-  controller_->RemoveBitrateObserver(&bitrate_observer_3);
+  bandwidth_observer_->OnReceivedEstimatedBitrate(1);
+  EXPECT_EQ(100000u, bitrate_observer_.last_bitrate_);
 }