Periodically update codec bit/frame rate settings.

webrtc/video/vie_encoder_unittest.cc

 /*
  *  Copyright (c) 2016 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 194 matching lines @@
 }  // namespace
 
 class ViEEncoderTest : public ::testing::Test {
  public:
   static const int kDefaultTimeoutMs = 30 * 1000;
 
   ViEEncoderTest()
       : video_send_config_(VideoSendStream::Config(nullptr)),
         codec_width_(320),
         codec_height_(240),
+        max_framerate_(30),
         fake_encoder_(),
         stats_proxy_(new MockableSendStatisticsProxy(
             Clock::GetRealTimeClock(),
             video_send_config_,
             webrtc::VideoEncoderConfig::ContentType::kRealtimeVideo)),
         sink_(&fake_encoder_) {}
 
   void SetUp() override {
     metrics::Reset();
     video_send_config_ = VideoSendStream::Config(nullptr);
     video_send_config_.encoder_settings.encoder = &fake_encoder_;
     video_send_config_.encoder_settings.payload_name = "FAKE";
     video_send_config_.encoder_settings.payload_type = 125;
 
     VideoEncoderConfig video_encoder_config;
     test::FillEncoderConfiguration(1, &video_encoder_config);
+    video_encoder_config.video_stream_factory =
+        new rtc::RefCountedObject<VideoStreamFactory>(1);
     video_encoder_config_ = video_encoder_config.Copy();
+
+    // Framerate limit is specified by the VideoStreamFactory.
+    std::vector<VideoStream> streams =
+        video_encoder_config.video_stream_factory->CreateEncoderStreams(
+            codec_width_, codec_height_, video_encoder_config);
+    max_framerate_ = streams[0].max_framerate;
+    fake_clock_.SetTimeMicros(1234);
+
     ConfigureEncoder(std::move(video_encoder_config), true /* nack_enabled */);
   }
 
   void ConfigureEncoder(VideoEncoderConfig video_encoder_config,
                         bool nack_enabled) {
     if (vie_encoder_)
       vie_encoder_->Stop();
     vie_encoder_.reset(new ViEEncoderUnderTest(
         stats_proxy_.get(), video_send_config_.encoder_settings));
     vie_encoder_->SetSink(&sink_, false /* rotation_applied */);
     vie_encoder_->SetSource(
         &video_source_,
         VideoSendStream::DegradationPreference::kMaintainFramerate);
     vie_encoder_->SetStartBitrate(kTargetBitrateBps);
     vie_encoder_->ConfigureEncoder(std::move(video_encoder_config),
                                    kMaxPayloadLength, nack_enabled);
     vie_encoder_->WaitUntilTaskQueueIsIdle();
   }
 
   void ResetEncoder(const std::string& payload_name,
                     size_t num_streams,
                     size_t num_temporal_layers,
-                    bool nack_enabled) {
+                    bool nack_enabled,
+                    bool screenshare) {
     video_send_config_.encoder_settings.payload_name = payload_name;
 
     VideoEncoderConfig video_encoder_config;
     video_encoder_config.number_of_streams = num_streams;
     video_encoder_config.max_bitrate_bps = kTargetBitrateBps;
     video_encoder_config.video_stream_factory =
         new rtc::RefCountedObject<VideoStreamFactory>(num_temporal_layers);
+    video_encoder_config.content_type =
+        screenshare ? VideoEncoderConfig::ContentType::kScreen
+                    : VideoEncoderConfig::ContentType::kRealtimeVideo;
     ConfigureEncoder(std::move(video_encoder_config), nack_enabled);
   }
 
   VideoFrame CreateFrame(int64_t ntp_time_ms,
                          rtc::Event* destruction_event) const {
     VideoFrame frame(new rtc::RefCountedObject<TestBuffer>(
                          destruction_event, codec_width_, codec_height_),
                      99, 99, kVideoRotation_0);
     frame.set_ntp_time_ms(ntp_time_ms);
     return frame;
@@ skipping 14 matching lines @@
     EXPECT_EQ(std::numeric_limits<int>::max(), wants.max_framerate_fps);
   }
 
   void VerifyResolutionLimitationLessThan(const rtc::VideoSinkWants& wants,
                                           int pixel_count) {
     EXPECT_LT(wants.max_pixel_count, pixel_count);
     EXPECT_GT(wants.max_pixel_count, 0);
     EXPECT_EQ(std::numeric_limits<int>::max(), wants.max_framerate_fps);
   }
 
+  void WaitForEncodedFrame(int64_t expected_ntp_time) {
+    sink_.WaitForEncodedFrame(expected_ntp_time);
+    fake_clock_.AdvanceTimeMicros(rtc::kNumMicrosecsPerSec / max_framerate_);
+  }
+
+  bool TimedWaitForEncodedFrame(int64_t expected_ntp_time, int64_t timeout_ms) {
+    bool ok = sink_.TimedWaitForEncodedFrame(expected_ntp_time, timeout_ms);
+    fake_clock_.AdvanceTimeMicros(rtc::kNumMicrosecsPerSec / max_framerate_);
+    return ok;
+  }
+
+  void WaitForEncodedFrame(uint32_t expected_width, uint32_t expected_height) {
+    sink_.WaitForEncodedFrame(expected_width, expected_height);
+    fake_clock_.AdvanceTimeMicros(rtc::kNumMicrosecsPerSec / max_framerate_);
+  }
+
+  void ExpectDroppedFrame() {
+    sink_.ExpectDroppedFrame();
+    fake_clock_.AdvanceTimeMicros(rtc::kNumMicrosecsPerSec / max_framerate_);
+  }
+
+  bool WaitForFrame(int64_t timeout_ms) {
+    bool ok = sink_.WaitForFrame(timeout_ms);
+    fake_clock_.AdvanceTimeMicros(rtc::kNumMicrosecsPerSec / max_framerate_);
+    return ok;
+  }
+
   class TestEncoder : public test::FakeEncoder {
    public:
     TestEncoder()
         : FakeEncoder(Clock::GetRealTimeClock()),
           continue_encode_event_(false, false) {}
 
     VideoCodec codec_config() const {
       rtc::CritScope lock(&crit_sect_);
       return config_;
     }
@@ skipping 88 matching lines @@
         GUARDED_BY(local_crit_sect_);
     bool force_init_encode_failed_ GUARDED_BY(local_crit_sect_) = false;
   };
 
   class TestSink : public ViEEncoder::EncoderSink {
    public:
     explicit TestSink(TestEncoder* test_encoder)
         : test_encoder_(test_encoder), encoded_frame_event_(false, false) {}
 
     void WaitForEncodedFrame(int64_t expected_ntp_time) {
+      EXPECT_TRUE(
+          TimedWaitForEncodedFrame(expected_ntp_time, kDefaultTimeoutMs));
+    }
+
+    bool TimedWaitForEncodedFrame(int64_t expected_ntp_time,
+                                  int64_t timeout_ms) {
       uint32_t timestamp = 0;
-      EXPECT_TRUE(encoded_frame_event_.Wait(kDefaultTimeoutMs));
+      if (!encoded_frame_event_.Wait(timeout_ms))
+        return false;
       {
         rtc::CritScope lock(&crit_);
         timestamp = last_timestamp_;
       }
       test_encoder_->CheckLastTimeStampsMatch(expected_ntp_time, timestamp);
+      return true;
     }
 
     void WaitForEncodedFrame(uint32_t expected_width,
                              uint32_t expected_height) {
       EXPECT_TRUE(encoded_frame_event_.Wait(kDefaultTimeoutMs));
       CheckLastFrameSizeMathces(expected_width, expected_height);
     }
 
     void CheckLastFrameSizeMathces(uint32_t expected_width,
                                    uint32_t expected_height) {
@@ skipping 58 matching lines @@
     uint32_t last_width_ = 0;
     bool expect_frames_ = true;
     int number_of_reconfigurations_ = 0;
     int min_transmit_bitrate_bps_ = 0;
   };
 
   VideoSendStream::Config video_send_config_;
   VideoEncoderConfig video_encoder_config_;
   int codec_width_;
   int codec_height_;
+  int max_framerate_;
   TestEncoder fake_encoder_;
   std::unique_ptr<MockableSendStatisticsProxy> stats_proxy_;
   TestSink sink_;
   AdaptingFrameForwarder video_source_;
   std::unique_ptr<ViEEncoderUnderTest> vie_encoder_;
+  rtc::ScopedFakeClock fake_clock_;
 };
 
 TEST_F(ViEEncoderTest, EncodeOneFrame) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
   rtc::Event frame_destroyed_event(false, false);
   video_source_.IncomingCapturedFrame(CreateFrame(1, &frame_destroyed_event));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   EXPECT_TRUE(frame_destroyed_event.Wait(kDefaultTimeoutMs));
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, DropsFramesBeforeFirstOnBitrateUpdated) {
   // Dropped since no target bitrate has been set.
   rtc::Event frame_destroyed_event(false, false);
   video_source_.IncomingCapturedFrame(CreateFrame(1, &frame_destroyed_event));
   EXPECT_TRUE(frame_destroyed_event.Wait(kDefaultTimeoutMs));
 
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   video_source_.IncomingCapturedFrame(CreateFrame(2, nullptr));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, DropsFramesWhenRateSetToZero) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
   video_source_.IncomingCapturedFrame(CreateFrame(1, nullptr));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
 
   vie_encoder_->OnBitrateUpdated(0, 0, 0);
   // Dropped since bitrate is zero.
   video_source_.IncomingCapturedFrame(CreateFrame(2, nullptr));
 
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
   video_source_.IncomingCapturedFrame(CreateFrame(3, nullptr));
-  sink_.WaitForEncodedFrame(3);
+  WaitForEncodedFrame(3);
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, DropsFramesWithSameOrOldNtpTimestamp) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
   video_source_.IncomingCapturedFrame(CreateFrame(1, nullptr));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
 
   // This frame will be dropped since it has the same ntp timestamp.
   video_source_.IncomingCapturedFrame(CreateFrame(1, nullptr));
 
   video_source_.IncomingCapturedFrame(CreateFrame(2, nullptr));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, DropsFrameAfterStop) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   video_source_.IncomingCapturedFrame(CreateFrame(1, nullptr));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
 
   vie_encoder_->Stop();
   sink_.SetExpectNoFrames();
   rtc::Event frame_destroyed_event(false, false);
   video_source_.IncomingCapturedFrame(CreateFrame(2, &frame_destroyed_event));
   EXPECT_TRUE(frame_destroyed_event.Wait(kDefaultTimeoutMs));
 }
 
 TEST_F(ViEEncoderTest, DropsPendingFramesOnSlowEncode) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   fake_encoder_.BlockNextEncode();
   video_source_.IncomingCapturedFrame(CreateFrame(1, nullptr));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   // Here, the encoder thread will be blocked in the TestEncoder waiting for a
   // call to ContinueEncode.
   video_source_.IncomingCapturedFrame(CreateFrame(2, nullptr));
   video_source_.IncomingCapturedFrame(CreateFrame(3, nullptr));
   fake_encoder_.ContinueEncode();
-  sink_.WaitForEncodedFrame(3);
+  WaitForEncodedFrame(3);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, ConfigureEncoderTriggersOnEncoderConfigurationChanged) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
   EXPECT_EQ(0, sink_.number_of_reconfigurations());
 
   // Capture a frame and wait for it to synchronize with the encoder thread.
   video_source_.IncomingCapturedFrame(CreateFrame(1, nullptr));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   // The encoder will have been configured once when the first frame is
   // received.
   EXPECT_EQ(1, sink_.number_of_reconfigurations());
 
   VideoEncoderConfig video_encoder_config;
   test::FillEncoderConfiguration(1, &video_encoder_config);
   video_encoder_config.min_transmit_bitrate_bps = 9999;
   vie_encoder_->ConfigureEncoder(std::move(video_encoder_config),
                                  kMaxPayloadLength, true /* nack_enabled */);
 
   // Capture a frame and wait for it to synchronize with the encoder thread.
   video_source_.IncomingCapturedFrame(CreateFrame(2, nullptr));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
   EXPECT_EQ(2, sink_.number_of_reconfigurations());
   EXPECT_EQ(9999, sink_.last_min_transmit_bitrate());
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, FrameResolutionChangeReconfigureEncoder) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Capture a frame and wait for it to synchronize with the encoder thread.
   video_source_.IncomingCapturedFrame(CreateFrame(1, nullptr));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   // The encoder will have been configured once.
   EXPECT_EQ(1, sink_.number_of_reconfigurations());
   EXPECT_EQ(codec_width_, fake_encoder_.codec_config().width);
   EXPECT_EQ(codec_height_, fake_encoder_.codec_config().height);
 
   codec_width_ *= 2;
   codec_height_ *= 2;
   // Capture a frame with a higher resolution and wait for it to synchronize
   // with the encoder thread.
   video_source_.IncomingCapturedFrame(CreateFrame(2, nullptr));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
   EXPECT_EQ(codec_width_, fake_encoder_.codec_config().width);
   EXPECT_EQ(codec_height_, fake_encoder_.codec_config().height);
   EXPECT_EQ(2, sink_.number_of_reconfigurations());
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, Vp8ResilienceIsOffFor1S1TLWithNackEnabled) {
   const bool kNackEnabled = true;
   const size_t kNumStreams = 1;
   const size_t kNumTl = 1;
-  ResetEncoder("VP8", kNumStreams, kNumTl, kNackEnabled);
+  ResetEncoder("VP8", kNumStreams, kNumTl, kNackEnabled, false);
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Capture a frame and wait for it to synchronize with the encoder thread.
   video_source_.IncomingCapturedFrame(CreateFrame(1, nullptr));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   // The encoder have been configured once when the first frame is received.
   EXPECT_EQ(1, sink_.number_of_reconfigurations());
   EXPECT_EQ(kVideoCodecVP8, fake_encoder_.codec_config().codecType);
   EXPECT_EQ(kNumStreams, fake_encoder_.codec_config().numberOfSimulcastStreams);
   EXPECT_EQ(kNumTl, fake_encoder_.codec_config().VP8()->numberOfTemporalLayers);
   // Resilience is off for no temporal layers with nack on.
   EXPECT_EQ(kResilienceOff, fake_encoder_.codec_config().VP8()->resilience);
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, Vp8ResilienceIsOffFor2S1TlWithNackEnabled) {
   const bool kNackEnabled = true;
   const size_t kNumStreams = 2;
   const size_t kNumTl = 1;
-  ResetEncoder("VP8", kNumStreams, kNumTl, kNackEnabled);
+  ResetEncoder("VP8", kNumStreams, kNumTl, kNackEnabled, false);
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Capture a frame and wait for it to synchronize with the encoder thread.
   video_source_.IncomingCapturedFrame(CreateFrame(1, nullptr));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   // The encoder have been configured once when the first frame is received.
   EXPECT_EQ(1, sink_.number_of_reconfigurations());
   EXPECT_EQ(kVideoCodecVP8, fake_encoder_.codec_config().codecType);
   EXPECT_EQ(kNumStreams, fake_encoder_.codec_config().numberOfSimulcastStreams);
   EXPECT_EQ(kNumTl, fake_encoder_.codec_config().VP8()->numberOfTemporalLayers);
   // Resilience is off for no temporal layers and >1 streams with nack on.
   EXPECT_EQ(kResilienceOff, fake_encoder_.codec_config().VP8()->resilience);
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, Vp8ResilienceIsOnFor1S1TLWithNackDisabled) {
   const bool kNackEnabled = false;
   const size_t kNumStreams = 1;
   const size_t kNumTl = 1;
-  ResetEncoder("VP8", kNumStreams, kNumTl, kNackEnabled);
+  ResetEncoder("VP8", kNumStreams, kNumTl, kNackEnabled, false);
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Capture a frame and wait for it to synchronize with the encoder thread.
   video_source_.IncomingCapturedFrame(CreateFrame(1, nullptr));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   // The encoder have been configured once when the first frame is received.
   EXPECT_EQ(1, sink_.number_of_reconfigurations());
   EXPECT_EQ(kVideoCodecVP8, fake_encoder_.codec_config().codecType);
   EXPECT_EQ(kNumStreams, fake_encoder_.codec_config().numberOfSimulcastStreams);
   EXPECT_EQ(kNumTl, fake_encoder_.codec_config().VP8()->numberOfTemporalLayers);
   // Resilience is on for no temporal layers with nack off.
   EXPECT_EQ(kResilientStream, fake_encoder_.codec_config().VP8()->resilience);
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, Vp8ResilienceIsOnFor1S2TlWithNackEnabled) {
   const bool kNackEnabled = true;
   const size_t kNumStreams = 1;
   const size_t kNumTl = 2;
-  ResetEncoder("VP8", kNumStreams, kNumTl, kNackEnabled);
+  ResetEncoder("VP8", kNumStreams, kNumTl, kNackEnabled, false);
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Capture a frame and wait for it to synchronize with the encoder thread.
   video_source_.IncomingCapturedFrame(CreateFrame(1, nullptr));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   // The encoder have been configured once when the first frame is received.
   EXPECT_EQ(1, sink_.number_of_reconfigurations());
   EXPECT_EQ(kVideoCodecVP8, fake_encoder_.codec_config().codecType);
   EXPECT_EQ(kNumStreams, fake_encoder_.codec_config().numberOfSimulcastStreams);
   EXPECT_EQ(kNumTl, fake_encoder_.codec_config().VP8()->numberOfTemporalLayers);
   // Resilience is on for temporal layers.
   EXPECT_EQ(kResilientStream, fake_encoder_.codec_config().VP8()->resilience);
   vie_encoder_->Stop();
 }
 
@@ skipping 23 matching lines @@
   VerifyNoLimitation(video_source_.sink_wants());
 
   int frame_width = 1280;
   int frame_height = 720;
 
   // Trigger CPU overuse kMaxCpuDowngrades times. Every time, ViEEncoder should
   // request lower resolution.
   for (int i = 1; i <= kMaxDowngrades; ++i) {
     video_source_.IncomingCapturedFrame(
         CreateFrame(i, frame_width, frame_height));
-    sink_.WaitForEncodedFrame(i);
+    WaitForEncodedFrame(i);
 
     vie_encoder_->TriggerCpuOveruse();
 
     EXPECT_FALSE(video_source_.sink_wants().target_pixel_count);
     EXPECT_LT(video_source_.sink_wants().max_pixel_count,
               frame_width * frame_height);
     EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
     EXPECT_EQ(i, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
     frame_width /= 2;
     frame_height /= 2;
   }
 
   // Trigger CPU overuse one more time. This should not trigger a request for
   // lower resolution.
   rtc::VideoSinkWants current_wants = video_source_.sink_wants();
   video_source_.IncomingCapturedFrame(
       CreateFrame(kMaxDowngrades + 1, frame_width, frame_height));
-  sink_.WaitForEncodedFrame(kMaxDowngrades + 1);
+  WaitForEncodedFrame(kMaxDowngrades + 1);
   vie_encoder_->TriggerCpuOveruse();
   EXPECT_EQ(video_source_.sink_wants().target_pixel_count,
             current_wants.target_pixel_count);
   EXPECT_EQ(video_source_.sink_wants().max_pixel_count,
             current_wants.max_pixel_count);
   EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(kMaxDowngrades,
             stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   // Trigger CPU normal use.
@@ skipping 14 matching lines @@
   VerifyNoLimitation(video_source_.sink_wants());
 
   const int kFrameWidth = 1280;
   const int kFrameHeight = 720;
   const int kFrameIntervalMs = 1000 / 30;
 
   int frame_timestamp = 1;
 
   video_source_.IncomingCapturedFrame(
       CreateFrame(frame_timestamp, kFrameWidth, kFrameHeight));
-  sink_.WaitForEncodedFrame(frame_timestamp);
+  WaitForEncodedFrame(frame_timestamp);
   frame_timestamp += kFrameIntervalMs;
 
   // Trigger CPU overuse.
   vie_encoder_->TriggerCpuOveruse();
   video_source_.IncomingCapturedFrame(
       CreateFrame(frame_timestamp, kFrameWidth, kFrameHeight));
-  sink_.WaitForEncodedFrame(frame_timestamp);
+  WaitForEncodedFrame(frame_timestamp);
   frame_timestamp += kFrameIntervalMs;
 
   // Default degradation preference is maintain-framerate, so will lower max
   // wanted resolution.
   EXPECT_FALSE(video_source_.sink_wants().target_pixel_count);
   EXPECT_LT(video_source_.sink_wants().max_pixel_count,
             kFrameWidth * kFrameHeight);
   EXPECT_EQ(std::numeric_limits<int>::max(),
             video_source_.sink_wants().max_framerate_fps);
 
   // Set new source, switch to maintain-resolution.
   test::FrameForwarder new_video_source;
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kMaintainResolution);
 
   // Initially no degradation registered.
   VerifyNoLimitation(new_video_source.sink_wants());
 
   // Force an input frame rate to be available, or the adaptation call won't
   // know what framerate to adapt form.
   const int kInputFps = 30;
   VideoSendStream::Stats stats = stats_proxy_->GetStats();
   stats.input_frame_rate = kInputFps;
   stats_proxy_->SetMockStats(stats);
 
   vie_encoder_->TriggerCpuOveruse();
   new_video_source.IncomingCapturedFrame(
       CreateFrame(frame_timestamp, kFrameWidth, kFrameHeight));
-  sink_.WaitForEncodedFrame(frame_timestamp);
+  WaitForEncodedFrame(frame_timestamp);
   frame_timestamp += kFrameIntervalMs;
 
   // Some framerate constraint should be set.
   EXPECT_FALSE(new_video_source.sink_wants().target_pixel_count);
   EXPECT_EQ(std::numeric_limits<int>::max(),
             new_video_source.sink_wants().max_pixel_count);
   EXPECT_LT(new_video_source.sink_wants().max_framerate_fps, kInputFps);
 
   // Turn off degradation completely.
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kDegradationDisabled);
   VerifyNoLimitation(new_video_source.sink_wants());
 
   vie_encoder_->TriggerCpuOveruse();
   new_video_source.IncomingCapturedFrame(
       CreateFrame(frame_timestamp, kFrameWidth, kFrameHeight));
-  sink_.WaitForEncodedFrame(frame_timestamp);
+  WaitForEncodedFrame(frame_timestamp);
   frame_timestamp += kFrameIntervalMs;
 
   // Still no degradation.
   VerifyNoLimitation(new_video_source.sink_wants());
 
   // Calling SetSource with resolution scaling enabled apply the old SinkWants.
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kMaintainFramerate);
   EXPECT_LT(new_video_source.sink_wants().max_pixel_count,
@@ skipping 13 matching lines @@
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, StatsTracksQualityAdaptationStats) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   const int kWidth = 1280;
   const int kHeight = 720;
   video_source_.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   VideoSendStream::Stats stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.bw_limited_resolution);
   EXPECT_EQ(0, stats.number_of_quality_adapt_changes);
 
   // Trigger adapt down.
   vie_encoder_->TriggerQualityLow();
   video_source_.IncomingCapturedFrame(CreateFrame(2, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
 
   stats = stats_proxy_->GetStats();
   EXPECT_TRUE(stats.bw_limited_resolution);
   EXPECT_EQ(1, stats.number_of_quality_adapt_changes);
 
   // Trigger adapt up.
   vie_encoder_->TriggerQualityHigh();
   video_source_.IncomingCapturedFrame(CreateFrame(3, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(3);
+  WaitForEncodedFrame(3);
 
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.bw_limited_resolution);
   EXPECT_EQ(2, stats.number_of_quality_adapt_changes);
   EXPECT_EQ(0, stats.number_of_cpu_adapt_changes);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, StatsTracksCpuAdaptationStats) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   const int kWidth = 1280;
   const int kHeight = 720;
   video_source_.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   VideoSendStream::Stats stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(0, stats.number_of_cpu_adapt_changes);
 
   // Trigger CPU overuse.
   vie_encoder_->TriggerCpuOveruse();
   video_source_.IncomingCapturedFrame(CreateFrame(2, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
 
   stats = stats_proxy_->GetStats();
   EXPECT_TRUE(stats.cpu_limited_resolution);
   EXPECT_EQ(1, stats.number_of_cpu_adapt_changes);
 
   // Trigger CPU normal use.
   vie_encoder_->TriggerCpuNormalUsage();
   video_source_.IncomingCapturedFrame(CreateFrame(3, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(3);
+  WaitForEncodedFrame(3);
 
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(2, stats.number_of_cpu_adapt_changes);
   EXPECT_EQ(0, stats.number_of_quality_adapt_changes);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, SwitchingSourceKeepsCpuAdaptation) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   const int kWidth = 1280;
   const int kHeight = 720;
   video_source_.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   VideoSendStream::Stats stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(0, stats.number_of_cpu_adapt_changes);
 
   // Trigger CPU overuse.
   vie_encoder_->TriggerCpuOveruse();
   video_source_.IncomingCapturedFrame(CreateFrame(2, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
   stats = stats_proxy_->GetStats();
   EXPECT_TRUE(stats.cpu_limited_resolution);
   EXPECT_EQ(1, stats.number_of_cpu_adapt_changes);
 
   // Set new source with adaptation still enabled.
   test::FrameForwarder new_video_source;
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kMaintainFramerate);
 
   new_video_source.IncomingCapturedFrame(CreateFrame(3, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(3);
+  WaitForEncodedFrame(3);
   stats = stats_proxy_->GetStats();
   EXPECT_TRUE(stats.cpu_limited_resolution);
   EXPECT_EQ(1, stats.number_of_cpu_adapt_changes);
 
   // Set adaptation disabled.
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kDegradationDisabled);
 
   new_video_source.IncomingCapturedFrame(CreateFrame(4, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(4);
+  WaitForEncodedFrame(4);
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(1, stats.number_of_cpu_adapt_changes);
 
   // Set adaptation back to enabled.
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kMaintainFramerate);
 
   new_video_source.IncomingCapturedFrame(CreateFrame(5, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(5);
+  WaitForEncodedFrame(5);
   stats = stats_proxy_->GetStats();
   EXPECT_TRUE(stats.cpu_limited_resolution);
   EXPECT_EQ(1, stats.number_of_cpu_adapt_changes);
 
   // Trigger CPU normal use.
   vie_encoder_->TriggerCpuNormalUsage();
   new_video_source.IncomingCapturedFrame(CreateFrame(6, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(6);
+  WaitForEncodedFrame(6);
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(2, stats.number_of_cpu_adapt_changes);
   EXPECT_EQ(0, stats.number_of_quality_adapt_changes);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, SwitchingSourceKeepsQualityAdaptation) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   const int kWidth = 1280;
   const int kHeight = 720;
   video_source_.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   VideoSendStream::Stats stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_FALSE(stats.bw_limited_resolution);
   EXPECT_EQ(0, stats.number_of_quality_adapt_changes);
 
   // Set new source with adaptation still enabled.
   test::FrameForwarder new_video_source;
   vie_encoder_->SetSource(&new_video_source,
                           VideoSendStream::DegradationPreference::kBalanced);
 
   new_video_source.IncomingCapturedFrame(CreateFrame(2, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_FALSE(stats.bw_limited_resolution);
   EXPECT_EQ(0, stats.number_of_quality_adapt_changes);
 
   // Trigger adapt down.
   vie_encoder_->TriggerQualityLow();
   new_video_source.IncomingCapturedFrame(CreateFrame(3, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(3);
+  WaitForEncodedFrame(3);
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_TRUE(stats.bw_limited_resolution);
   EXPECT_EQ(1, stats.number_of_quality_adapt_changes);
 
   // Set new source with adaptation still enabled.
   vie_encoder_->SetSource(&new_video_source,
                           VideoSendStream::DegradationPreference::kBalanced);
 
   new_video_source.IncomingCapturedFrame(CreateFrame(4, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(4);
+  WaitForEncodedFrame(4);
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_TRUE(stats.bw_limited_resolution);
   EXPECT_EQ(1, stats.number_of_quality_adapt_changes);
 
   // Disable resolution scaling.
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kMaintainResolution);
 
   new_video_source.IncomingCapturedFrame(CreateFrame(5, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(5);
+  WaitForEncodedFrame(5);
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_FALSE(stats.bw_limited_resolution);
   EXPECT_EQ(1, stats.number_of_quality_adapt_changes);
   EXPECT_EQ(0, stats.number_of_cpu_adapt_changes);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, QualityAdaptationStatsAreResetWhenScalerIsDisabled) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   const int kWidth = 1280;
   const int kHeight = 720;
   video_source_.set_adaptation_enabled(true);
   video_source_.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_FALSE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   // Trigger adapt down.
   vie_encoder_->TriggerQualityLow();
   video_source_.IncomingCapturedFrame(CreateFrame(2, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_TRUE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   // Trigger overuse.
   vie_encoder_->TriggerCpuOveruse();
   video_source_.IncomingCapturedFrame(CreateFrame(3, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(3);
+  WaitForEncodedFrame(3);
   EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_TRUE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(1, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   // Set source with adaptation still enabled but quality scaler is off.
   fake_encoder_.SetQualityScaling(false);
   vie_encoder_->SetSource(
       &video_source_,
       VideoSendStream::DegradationPreference::kMaintainFramerate);
 
   video_source_.IncomingCapturedFrame(CreateFrame(4, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(4);
+  WaitForEncodedFrame(4);
   EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_FALSE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(1, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, StatsTracksCpuAdaptationStatsWhenSwitchingSource) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   const int kWidth = 1280;
   const int kHeight = 720;
   int sequence = 1;
 
   video_source_.IncomingCapturedFrame(CreateFrame(sequence, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(sequence++);
+  WaitForEncodedFrame(sequence++);
   VideoSendStream::Stats stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(0, stats.number_of_cpu_adapt_changes);
 
   // Trigger CPU overuse, should now adapt down.
   vie_encoder_->TriggerCpuOveruse();
   video_source_.IncomingCapturedFrame(CreateFrame(sequence, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(sequence++);
+  WaitForEncodedFrame(sequence++);
   stats = stats_proxy_->GetStats();
   EXPECT_TRUE(stats.cpu_limited_resolution);
   EXPECT_EQ(1, stats.number_of_cpu_adapt_changes);
 
   // Set new source with adaptation still enabled.
   test::FrameForwarder new_video_source;
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kMaintainFramerate);
 
   new_video_source.IncomingCapturedFrame(
       CreateFrame(sequence, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(sequence++);
+  WaitForEncodedFrame(sequence++);
   stats = stats_proxy_->GetStats();
   EXPECT_TRUE(stats.cpu_limited_resolution);
   EXPECT_EQ(1, stats.number_of_cpu_adapt_changes);
 
   // Set cpu adaptation by frame dropping.
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kMaintainResolution);
   new_video_source.IncomingCapturedFrame(
       CreateFrame(sequence, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(sequence++);
+  WaitForEncodedFrame(sequence++);
   stats = stats_proxy_->GetStats();
   // Not adapted at first.
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(1, stats.number_of_cpu_adapt_changes);
 
   // Force an input frame rate to be available, or the adaptation call won't
   // know what framerate to adapt form.
   VideoSendStream::Stats mock_stats = stats_proxy_->GetStats();
   mock_stats.input_frame_rate = 30;
   stats_proxy_->SetMockStats(mock_stats);
   vie_encoder_->TriggerCpuOveruse();
   stats_proxy_->ResetMockStats();
 
   new_video_source.IncomingCapturedFrame(
       CreateFrame(sequence, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(sequence++);
+  WaitForEncodedFrame(sequence++);
 
   // Framerate now adapted.
   stats = stats_proxy_->GetStats();
   EXPECT_TRUE(stats.cpu_limited_resolution);
   EXPECT_EQ(2, stats.number_of_cpu_adapt_changes);
 
   // Disable CPU adaptation.
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kDegradationDisabled);
   new_video_source.IncomingCapturedFrame(
       CreateFrame(sequence, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(sequence++);
+  WaitForEncodedFrame(sequence++);
 
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(2, stats.number_of_cpu_adapt_changes);
 
   // Try to trigger overuse. Should not succeed.
   stats_proxy_->SetMockStats(mock_stats);
   vie_encoder_->TriggerCpuOveruse();
   stats_proxy_->ResetMockStats();
 
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(2, stats.number_of_cpu_adapt_changes);
 
   // Switch back the source with resolution adaptation enabled.
   vie_encoder_->SetSource(
       &video_source_,
       VideoSendStream::DegradationPreference::kMaintainFramerate);
   video_source_.IncomingCapturedFrame(CreateFrame(sequence, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(sequence++);
+  WaitForEncodedFrame(sequence++);
   stats = stats_proxy_->GetStats();
   EXPECT_TRUE(stats.cpu_limited_resolution);
   EXPECT_EQ(2, stats.number_of_cpu_adapt_changes);
 
   // Trigger CPU normal usage.
   vie_encoder_->TriggerCpuNormalUsage();
   video_source_.IncomingCapturedFrame(CreateFrame(sequence, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(sequence++);
+  WaitForEncodedFrame(sequence++);
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(3, stats.number_of_cpu_adapt_changes);
 
   // Back to the source with adaptation off, set it back to maintain-resolution.
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kMaintainResolution);
   new_video_source.IncomingCapturedFrame(
       CreateFrame(sequence, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(sequence++);
+  WaitForEncodedFrame(sequence++);
   stats = stats_proxy_->GetStats();
   // Disabled, since we previously switched the source too disabled.
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(3, stats.number_of_cpu_adapt_changes);
 
   // Trigger CPU normal usage.
   vie_encoder_->TriggerCpuNormalUsage();
   new_video_source.IncomingCapturedFrame(
       CreateFrame(sequence, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(sequence++);
+  WaitForEncodedFrame(sequence++);
   stats = stats_proxy_->GetStats();
   EXPECT_FALSE(stats.cpu_limited_resolution);
   EXPECT_EQ(4, stats.number_of_cpu_adapt_changes);
   EXPECT_EQ(0, stats.number_of_quality_adapt_changes);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, StatsTracksPreferredBitrate) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   const int kWidth = 1280;
   const int kHeight = 720;
   video_source_.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
 
   VideoSendStream::Stats stats = stats_proxy_->GetStats();
   EXPECT_EQ(video_encoder_config_.max_bitrate_bps,
             stats.preferred_media_bitrate_bps);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, ScalingUpAndDownDoesNothingWithMaintainResolution) {
   const int kWidth = 1280;
   const int kHeight = 720;
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Expect no scaling to begin with.
   VerifyNoLimitation(video_source_.sink_wants());
 
   video_source_.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
 
   // Trigger scale down.
   vie_encoder_->TriggerQualityLow();
 
   video_source_.IncomingCapturedFrame(CreateFrame(2, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
 
   // Expect a scale down.
   EXPECT_TRUE(video_source_.sink_wants().max_pixel_count);
   EXPECT_LT(video_source_.sink_wants().max_pixel_count, kWidth * kHeight);
 
   // Set resolution scaling disabled.
   test::FrameForwarder new_video_source;
   vie_encoder_->SetSource(
       &new_video_source,
       VideoSendStream::DegradationPreference::kMaintainResolution);
 
   // Trigger scale down.
   vie_encoder_->TriggerQualityLow();
   new_video_source.IncomingCapturedFrame(CreateFrame(3, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(3);
+  WaitForEncodedFrame(3);
 
   // Expect no scaling.
   EXPECT_EQ(std::numeric_limits<int>::max(),
             new_video_source.sink_wants().max_pixel_count);
 
   // Trigger scale up.
   vie_encoder_->TriggerQualityHigh();
   new_video_source.IncomingCapturedFrame(CreateFrame(4, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(4);
+  WaitForEncodedFrame(4);
 
   // Expect nothing to change, still no scaling.
   EXPECT_EQ(std::numeric_limits<int>::max(),
             new_video_source.sink_wants().max_pixel_count);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, SkipsSameAdaptDownRequest_MaintainFramerateMode) {
   const int kWidth = 1280;
   const int kHeight = 720;
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Enable kMaintainFramerate preference, no initial limitation.
   test::FrameForwarder source;
   vie_encoder_->SetSource(
       &source, VideoSendStream::DegradationPreference::kMaintainFramerate);
 
   source.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   // Trigger adapt down, expect scaled down resolution.
   vie_encoder_->TriggerCpuOveruse();
   VerifyResolutionLimitationLessThan(source.sink_wants(), kWidth * kHeight);
   const int kLastMaxPixelCount = source.sink_wants().max_pixel_count;
   EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(1, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
@@ skipping 11 matching lines @@
   const int kWidth = 1280;
   const int kHeight = 720;
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Enable kMaintainFramerate preference, no initial limitation.
   test::FrameForwarder source;
   vie_encoder_->SetSource(
       &source, VideoSendStream::DegradationPreference::kMaintainFramerate);
 
   source.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(kWidth, kHeight);
+  WaitForEncodedFrame(kWidth, kHeight);
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   // Trigger adapt up, expect no change.
   vie_encoder_->TriggerCpuNormalUsage();
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, NoChangeForInitialNormalUsage_MaintainResolutionMode) {
   const int kWidth = 1280;
   const int kHeight = 720;
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Enable kMaintainResolution preference, no initial limitation.
   test::FrameForwarder source;
   vie_encoder_->SetSource(
       &source, VideoSendStream::DegradationPreference::kMaintainResolution);
 
   source.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(kWidth, kHeight);
+  WaitForEncodedFrame(kWidth, kHeight);
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   // Trigger adapt up, expect no change.
   vie_encoder_->TriggerCpuNormalUsage();
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, AdaptsResolutionForLowQuality_MaintainFramerateMode) {
   const int kWidth = 1280;
   const int kHeight = 720;
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Enable kMaintainFramerate preference, no initial limitation.
   AdaptingFrameForwarder source;
   source.set_adaptation_enabled(true);
   vie_encoder_->SetSource(
       &source, VideoSendStream::DegradationPreference::kMaintainFramerate);
 
   source.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   // Trigger adapt down, expect scaled down resolution.
   vie_encoder_->TriggerQualityLow();
   source.IncomingCapturedFrame(CreateFrame(2, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
   VerifyResolutionLimitationLessThan(source.sink_wants(), kWidth * kHeight);
   EXPECT_TRUE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(1, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   // Trigger adapt up, expect no restriction.
   vie_encoder_->TriggerQualityHigh();
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(2, stats_proxy_->GetStats().number_of_quality_adapt_changes);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
@@ skipping 11 matching lines @@
   // Enable adapter, expected input resolutions when downscaling:
   // 1280x720 -> 960x540 -> 640x360 -> 480x270 -> 320x180 (min resolution limit)
   video_source_.set_adaptation_enabled(true);
 
   EXPECT_FALSE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   int downscales = 0;
   for (size_t i = 1; i <= kNumFrames; i++) {
     video_source_.IncomingCapturedFrame(CreateFrame(i, kWidth, kHeight));
-    sink_.WaitForEncodedFrame(i);
+    WaitForEncodedFrame(i);
 
     // Trigger scale down.
     rtc::VideoSinkWants last_wants = video_source_.sink_wants();
     vie_encoder_->TriggerQualityLow();
     EXPECT_GE(video_source_.sink_wants().max_pixel_count, kMinPixelsPerFrame);
 
     if (video_source_.sink_wants().max_pixel_count < last_wants.max_pixel_count)
       ++downscales;
 
     EXPECT_TRUE(stats_proxy_->GetStats().bw_limited_resolution);
@@ skipping 10 matching lines @@
   const int kHeight = 720;
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Enable kMaintainFramerate preference, no initial limitation.
   AdaptingFrameForwarder source;
   source.set_adaptation_enabled(true);
   vie_encoder_->SetSource(
       &source, VideoSendStream::DegradationPreference::kMaintainFramerate);
 
   source.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   // Trigger adapt down, expect scaled down resolution.
   vie_encoder_->TriggerCpuOveruse();
   source.IncomingCapturedFrame(CreateFrame(2, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
   VerifyResolutionLimitationLessThan(source.sink_wants(), kWidth * kHeight);
   EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(1, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   // Trigger adapt up, expect no restriction.
   vie_encoder_->TriggerCpuNormalUsage();
   source.IncomingCapturedFrame(CreateFrame(3, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(3);
+  WaitForEncodedFrame(3);
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(2, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   // Trigger adapt down, expect scaled down resolution.
   vie_encoder_->TriggerCpuOveruse();
   source.IncomingCapturedFrame(CreateFrame(4, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(4);
+  WaitForEncodedFrame(4);
   VerifyResolutionLimitationLessThan(source.sink_wants(), kWidth * kHeight);
   EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(3, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   // Trigger adapt up, expect no restriction.
   vie_encoder_->TriggerCpuNormalUsage();
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(4, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest,
        AdaptsResolutionOnOveruseAndLowQuality_MaintainFramerateMode) {
   const int kWidth = 1280;
   const int kHeight = 720;
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Enable kMaintainFramerate preference, no initial limitation.
   AdaptingFrameForwarder source;
   source.set_adaptation_enabled(true);
   vie_encoder_->SetSource(
       &source, VideoSendStream::DegradationPreference::kMaintainFramerate);
 
   source.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(kWidth, kHeight);
+  WaitForEncodedFrame(kWidth, kHeight);
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_FALSE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   // Trigger cpu adapt down, expect scaled down resolution (960x540).
   vie_encoder_->TriggerCpuOveruse();
   source.IncomingCapturedFrame(CreateFrame(2, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(2);
+  WaitForEncodedFrame(2);
   VerifyResolutionLimitationLessThan(source.sink_wants(), kWidth * kHeight);
   rtc::VideoSinkWants last_wants = source.sink_wants();
   EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_FALSE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(1, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   // Trigger cpu adapt down, expect scaled down resolution (640x360).
   vie_encoder_->TriggerCpuOveruse();
   source.IncomingCapturedFrame(CreateFrame(3, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(3);
+  WaitForEncodedFrame(3);
   EXPECT_LT(source.sink_wants().max_pixel_count, last_wants.max_pixel_count);
   last_wants = source.sink_wants();
   EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_FALSE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(2, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   // Trigger cpu adapt down, max cpu downgrades reached, expect no change.
   vie_encoder_->TriggerCpuOveruse();
   source.IncomingCapturedFrame(CreateFrame(4, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(4);
+  WaitForEncodedFrame(4);
   EXPECT_EQ(last_wants.max_pixel_count, source.sink_wants().max_pixel_count);
   EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_FALSE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(2, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   // Trigger quality adapt down, expect scaled down resolution (480x270).
   vie_encoder_->TriggerQualityLow();
   source.IncomingCapturedFrame(CreateFrame(5, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(5);
+  WaitForEncodedFrame(5);
   EXPECT_LT(source.sink_wants().max_pixel_count, last_wants.max_pixel_count);
   last_wants = source.sink_wants();
   EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_TRUE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(2, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
   EXPECT_EQ(1, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   // Trigger cpu adapt up, expect upscaled resolution (640x360).
   vie_encoder_->TriggerCpuNormalUsage();
   source.IncomingCapturedFrame(CreateFrame(6, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(6);
+  WaitForEncodedFrame(6);
   EXPECT_GT(source.sink_wants().max_pixel_count, last_wants.max_pixel_count);
   last_wants = source.sink_wants();
   EXPECT_TRUE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_TRUE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(3, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
   EXPECT_EQ(1, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   // Trigger cpu adapt up, expect upscaled resolution (960x540).
   vie_encoder_->TriggerCpuNormalUsage();
   source.IncomingCapturedFrame(CreateFrame(7, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(7);
+  WaitForEncodedFrame(7);
   EXPECT_GT(source.sink_wants().max_pixel_count, last_wants.max_pixel_count);
   last_wants = source.sink_wants();
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_TRUE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(4, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
   EXPECT_EQ(1, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   // Trigger cpu adapt up, no cpu downgrades, expect no change (960x540).
   vie_encoder_->TriggerCpuNormalUsage();
   source.IncomingCapturedFrame(CreateFrame(8, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(8);
+  WaitForEncodedFrame(8);
   EXPECT_EQ(last_wants.max_pixel_count, source.sink_wants().max_pixel_count);
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_TRUE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(4, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
   EXPECT_EQ(1, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   // Trigger quality adapt up, expect no restriction (1280x720).
   vie_encoder_->TriggerQualityHigh();
   source.IncomingCapturedFrame(CreateFrame(9, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(kWidth, kHeight);
+  WaitForEncodedFrame(kWidth, kHeight);
   EXPECT_GT(source.sink_wants().max_pixel_count, last_wants.max_pixel_count);
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_FALSE(stats_proxy_->GetStats().bw_limited_resolution);
   EXPECT_EQ(4, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
   EXPECT_EQ(2, stats_proxy_->GetStats().number_of_quality_adapt_changes);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, CpuLimitedHistogramIsReported) {
-  vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
   const int kWidth = 640;
   const int kHeight = 360;
 
+  vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
+
   for (int i = 1; i <= SendStatisticsProxy::kMinRequiredMetricsSamples; ++i) {
     video_source_.IncomingCapturedFrame(CreateFrame(i, kWidth, kHeight));
-    sink_.WaitForEncodedFrame(i);
+    WaitForEncodedFrame(i);
   }
 
   vie_encoder_->TriggerCpuOveruse();
   for (int i = 1; i <= SendStatisticsProxy::kMinRequiredMetricsSamples; ++i) {
     video_source_.IncomingCapturedFrame(CreateFrame(
         SendStatisticsProxy::kMinRequiredMetricsSamples + i, kWidth, kHeight));
-    sink_.WaitForEncodedFrame(SendStatisticsProxy::kMinRequiredMetricsSamples +
-                              i);
+    WaitForEncodedFrame(SendStatisticsProxy::kMinRequiredMetricsSamples + i);
   }
 
   vie_encoder_->Stop();
   vie_encoder_.reset();
   stats_proxy_.reset();
 
   EXPECT_EQ(1,
             metrics::NumSamples("WebRTC.Video.CpuLimitedResolutionInPercent"));
   EXPECT_EQ(
       1, metrics::NumEvents("WebRTC.Video.CpuLimitedResolutionInPercent", 50));
 }
 
 TEST_F(ViEEncoderTest, CpuLimitedHistogramIsNotReportedForDisabledDegradation) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
   const int kWidth = 640;
   const int kHeight = 360;
 
   vie_encoder_->SetSource(
       &video_source_,
       VideoSendStream::DegradationPreference::kDegradationDisabled);
 
   for (int i = 1; i <= SendStatisticsProxy::kMinRequiredMetricsSamples; ++i) {
     video_source_.IncomingCapturedFrame(CreateFrame(i, kWidth, kHeight));
-    sink_.WaitForEncodedFrame(i);
+    WaitForEncodedFrame(i);
   }
 
   vie_encoder_->Stop();
   vie_encoder_.reset();
   stats_proxy_.reset();
 
   EXPECT_EQ(0,
             metrics::NumSamples("WebRTC.Video.CpuLimitedResolutionInPercent"));
 }
 
@@ skipping 10 matching lines @@
           .GetAllocation(kLowTargetBitrateBps, kDefaultFps);
 
   // First called on bitrate updated, then again on first frame.
   EXPECT_CALL(bitrate_observer, OnBitrateAllocationUpdated(expected_bitrate))
       .Times(2);
   vie_encoder_->OnBitrateUpdated(kLowTargetBitrateBps, 0, 0);
 
   const int64_t kStartTimeMs = 1;
   video_source_.IncomingCapturedFrame(
       CreateFrame(kStartTimeMs, codec_width_, codec_height_));
-  sink_.WaitForEncodedFrame(kStartTimeMs);
+  WaitForEncodedFrame(kStartTimeMs);
 
   // Not called on second frame.
   EXPECT_CALL(bitrate_observer, OnBitrateAllocationUpdated(expected_bitrate))
       .Times(0);
   video_source_.IncomingCapturedFrame(
       CreateFrame(kStartTimeMs + 1, codec_width_, codec_height_));
-  sink_.WaitForEncodedFrame(kStartTimeMs + 1);
+  WaitForEncodedFrame(kStartTimeMs + 1);
 
   // Called after a process interval.
   const int64_t kProcessIntervalMs =
       vcm::VCMProcessTimer::kDefaultProcessIntervalMs;
-  // TODO(sprang): ViEEncoder should die and/or get injectable clock.
-  // Sleep for one processing interval plus one frame to avoid flakiness.
-  SleepMs(kProcessIntervalMs + 1000 / kDefaultFps);
+  fake_clock_.AdvanceTimeMicros(rtc::kNumMicrosecsPerMillisec *
+                                (kProcessIntervalMs + (1000 / kDefaultFps)));
   EXPECT_CALL(bitrate_observer, OnBitrateAllocationUpdated(expected_bitrate))
       .Times(1);
   video_source_.IncomingCapturedFrame(CreateFrame(
       kStartTimeMs + kProcessIntervalMs, codec_width_, codec_height_));
-  sink_.WaitForEncodedFrame(kStartTimeMs + kProcessIntervalMs);
+  WaitForEncodedFrame(kStartTimeMs + kProcessIntervalMs);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, DropsFramesAndScalesWhenBitrateIsTooLow) {
   const int kTooLowBitrateForFrameSizeBps = 10000;
   vie_encoder_->OnBitrateUpdated(kTooLowBitrateForFrameSizeBps, 0, 0);
   const int kWidth = 640;
   const int kHeight = 360;
 
   video_source_.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
 
   // Expect to drop this frame, the wait should time out.
-  sink_.ExpectDroppedFrame();
+  ExpectDroppedFrame();
 
   // Expect the sink_wants to specify a scaled frame.
   EXPECT_LT(video_source_.sink_wants().max_pixel_count, kWidth * kHeight);
 
   int last_pixel_count = video_source_.sink_wants().max_pixel_count;
 
   // Next frame is scaled.
   video_source_.IncomingCapturedFrame(
       CreateFrame(2, kWidth * 3 / 4, kHeight * 3 / 4));
 
   // Expect to drop this frame, the wait should time out.
-  sink_.ExpectDroppedFrame();
+  ExpectDroppedFrame();
 
   EXPECT_LT(video_source_.sink_wants().max_pixel_count, last_pixel_count);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, NrOfDroppedFramesLimitedWhenBitrateIsTooLow) {
   const int kTooLowBitrateForFrameSizeBps = 10000;
   vie_encoder_->OnBitrateUpdated(kTooLowBitrateForFrameSizeBps, 0, 0);
   const int kWidth = 640;
   const int kHeight = 360;
 
   // We expect the n initial frames to get dropped.
   int i;
   for (i = 1; i <= kMaxInitialFramedrop; ++i) {
     video_source_.IncomingCapturedFrame(CreateFrame(i, kWidth, kHeight));
-    sink_.ExpectDroppedFrame();
+    ExpectDroppedFrame();
   }
   // The n+1th frame should not be dropped, even though it's size is too large.
   video_source_.IncomingCapturedFrame(CreateFrame(i, kWidth, kHeight));
-  sink_.WaitForEncodedFrame(i);
+  WaitForEncodedFrame(i);
 
   // Expect the sink_wants to specify a scaled frame.
   EXPECT_LT(video_source_.sink_wants().max_pixel_count, kWidth * kHeight);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, InitialFrameDropOffWithMaintainResolutionPreference) {
   const int kWidth = 640;
   const int kHeight = 360;
   vie_encoder_->OnBitrateUpdated(kLowTargetBitrateBps, 0, 0);
 
   // Set degradation preference.
   vie_encoder_->SetSource(
       &video_source_,
       VideoSendStream::DegradationPreference::kMaintainResolution);
 
   video_source_.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
   // Frame should not be dropped, even if it's too large.
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, InitialFrameDropOffWhenEncoderDisabledScaling) {
   const int kWidth = 640;
   const int kHeight = 360;
   fake_encoder_.SetQualityScaling(false);
   vie_encoder_->OnBitrateUpdated(kLowTargetBitrateBps, 0, 0);
   // Force quality scaler reconfiguration by resetting the source.
   vie_encoder_->SetSource(&video_source_,
                           VideoSendStream::DegradationPreference::kBalanced);
 
   video_source_.IncomingCapturedFrame(CreateFrame(1, kWidth, kHeight));
   // Frame should not be dropped, even if it's too large.
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
 
   vie_encoder_->Stop();
   fake_encoder_.SetQualityScaling(true);
 }
 
 TEST_F(ViEEncoderTest,
        ResolutionNotAdaptedForTooSmallFrame_MaintainFramerateMode) {
   const int kTooSmallWidth = 10;
   const int kTooSmallHeight = 10;
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   // Enable kMaintainFramerate preference, no initial limitation.
   test::FrameForwarder source;
   vie_encoder_->SetSource(
       &source, VideoSendStream::DegradationPreference::kMaintainFramerate);
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
 
   // Trigger adapt down, too small frame, expect no change.
   source.IncomingCapturedFrame(CreateFrame(1, kTooSmallWidth, kTooSmallHeight));
-  sink_.WaitForEncodedFrame(1);
+  WaitForEncodedFrame(1);
   vie_encoder_->TriggerCpuOveruse();
   VerifyNoLimitation(source.sink_wants());
   EXPECT_FALSE(stats_proxy_->GetStats().cpu_limited_resolution);
   EXPECT_EQ(0, stats_proxy_->GetStats().number_of_cpu_adapt_changes);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, FailingInitEncodeDoesntCauseCrash) {
   fake_encoder_.ForceInitEncodeFailure(true);
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
-  ResetEncoder("VP8", 2, 1, true);
+  ResetEncoder("VP8", 2, 1, true, false);
   const int kFrameWidth = 1280;
   const int kFrameHeight = 720;
   video_source_.IncomingCapturedFrame(
       CreateFrame(1, kFrameWidth, kFrameHeight));
-  sink_.ExpectDroppedFrame();
+  ExpectDroppedFrame();
   vie_encoder_->Stop();
 }
 
 // TODO(sprang): Extend this with fps throttling and any "balanced" extensions.
 TEST_F(ViEEncoderTest, AdaptsResolutionOnOveruse_MaintainFramerateMode) {
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
 
   const int kFrameWidth = 1280;
   const int kFrameHeight = 720;
   // Enabled default VideoAdapter downscaling. First step is 3/4, not 3/5 as
   // requested by ViEEncoder::VideoSourceProxy::RequestResolutionLowerThan().
   video_source_.set_adaptation_enabled(true);
 
   video_source_.IncomingCapturedFrame(
       CreateFrame(1, kFrameWidth, kFrameHeight));
-  sink_.WaitForEncodedFrame(kFrameWidth, kFrameHeight);
+  WaitForEncodedFrame(kFrameWidth, kFrameHeight);
 
   // Trigger CPU overuse, downscale by 3/4.
   vie_encoder_->TriggerCpuOveruse();
   video_source_.IncomingCapturedFrame(
       CreateFrame(2, kFrameWidth, kFrameHeight));
-  sink_.WaitForEncodedFrame((kFrameWidth * 3) / 4, (kFrameHeight * 3) / 4);
+  WaitForEncodedFrame((kFrameWidth * 3) / 4, (kFrameHeight * 3) / 4);
 
   // Trigger CPU normal use, return to original resolution.
   vie_encoder_->TriggerCpuNormalUsage();
   video_source_.IncomingCapturedFrame(
       CreateFrame(3, kFrameWidth, kFrameHeight));
-  sink_.WaitForEncodedFrame(kFrameWidth, kFrameHeight);
+  WaitForEncodedFrame(kFrameWidth, kFrameHeight);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, AdaptsFramerateOnOveruse_MaintainResolutionMode) {
-  const int kDefaultFramerateFps = 30;
-  const int kFrameIntervalMs = rtc::kNumMillisecsPerSec / kDefaultFramerateFps;
+  // const int kDefaultFramerateFps = 30;
   const int kFrameWidth = 1280;
   const int kFrameHeight = 720;
-  rtc::ScopedFakeClock fake_clock;
+  int kFrameIntervalMs = rtc::kNumMillisecsPerSec / max_framerate_;
 
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
   vie_encoder_->SetSource(
       &video_source_,
       VideoSendStream::DegradationPreference::kMaintainResolution);
   video_source_.set_adaptation_enabled(true);
 
-  fake_clock.SetTimeMicros(kFrameIntervalMs * 1000);
-  int64_t timestamp_ms = kFrameIntervalMs;
+  int64_t timestamp_ms = fake_clock_.TimeNanos() / rtc::kNumNanosecsPerMillisec;
 
   video_source_.IncomingCapturedFrame(
       CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
-  sink_.WaitForEncodedFrame(timestamp_ms);
+  WaitForEncodedFrame(timestamp_ms);
 
   // Try to trigger overuse. No fps estimate available => no effect.
   vie_encoder_->TriggerCpuOveruse();
 
   // Insert frames for one second to get a stable estimate.
-  for (int i = 0; i < kDefaultFramerateFps; ++i) {
+  for (int i = 0; i < max_framerate_; ++i) {
     timestamp_ms += kFrameIntervalMs;
-    fake_clock.AdvanceTimeMicros(kFrameIntervalMs * 1000);
     video_source_.IncomingCapturedFrame(
         CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
-    sink_.WaitForEncodedFrame(timestamp_ms);
+    WaitForEncodedFrame(timestamp_ms);
   }
 
   // Trigger CPU overuse, reduce framerate by 2/3.
   vie_encoder_->TriggerCpuOveruse();
   int num_frames_dropped = 0;
-  for (int i = 0; i < kDefaultFramerateFps; ++i) {
+  for (int i = 0; i < max_framerate_; ++i) {
     timestamp_ms += kFrameIntervalMs;
-    fake_clock.AdvanceTimeMicros(kFrameIntervalMs * 1000);
     video_source_.IncomingCapturedFrame(
         CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
-    if (!sink_.WaitForFrame(kFrameTimeoutMs)) {
+    if (!WaitForFrame(kFrameTimeoutMs)) {
       ++num_frames_dropped;
     } else {
       sink_.CheckLastFrameSizeMathces(kFrameWidth, kFrameHeight);
     }
   }
 
-  // TODO(sprang): Find where there's rounding errors or stuff causing the
-  // margin here to be a little larger than we'd like (input fps estimate is
-  // off) and the frame dropping is a little too aggressive.
-  const int kErrorMargin = 5;
-  EXPECT_NEAR(num_frames_dropped,
-              kDefaultFramerateFps - (kDefaultFramerateFps * 2 / 3),
+  // Add some slack to account for frames dropped by the frame dropper.
+  const int kErrorMargin = 1;
+  EXPECT_NEAR(num_frames_dropped, max_framerate_ - (max_framerate_ * 2 / 3),
               kErrorMargin);
 
   // Trigger CPU overuse, reduce framerate by 2/3 again.
   vie_encoder_->TriggerCpuOveruse();
   num_frames_dropped = 0;
-  for (int i = 0; i < kDefaultFramerateFps; ++i) {
+  for (int i = 0; i < max_framerate_; ++i) {
     timestamp_ms += kFrameIntervalMs;
-    fake_clock.AdvanceTimeMicros(kFrameIntervalMs * 1000);
     video_source_.IncomingCapturedFrame(
         CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
-    if (!sink_.WaitForFrame(kFrameTimeoutMs)) {
+    if (!WaitForFrame(kFrameTimeoutMs)) {
       ++num_frames_dropped;
     } else {
       sink_.CheckLastFrameSizeMathces(kFrameWidth, kFrameHeight);
     }
   }
-  EXPECT_NEAR(num_frames_dropped,
-              kDefaultFramerateFps - (kDefaultFramerateFps * 4 / 9),
+  EXPECT_NEAR(num_frames_dropped, max_framerate_ - (max_framerate_ * 4 / 9),
               kErrorMargin);
 
   // Go back up one step.
   vie_encoder_->TriggerCpuNormalUsage();
   num_frames_dropped = 0;
-  for (int i = 0; i < kDefaultFramerateFps; ++i) {
+  for (int i = 0; i < max_framerate_; ++i) {
     timestamp_ms += kFrameIntervalMs;
-    fake_clock.AdvanceTimeMicros(kFrameIntervalMs * 1000);
     video_source_.IncomingCapturedFrame(
         CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
-    if (!sink_.WaitForFrame(kFrameTimeoutMs)) {
+    if (!WaitForFrame(kFrameTimeoutMs)) {
       ++num_frames_dropped;
     } else {
       sink_.CheckLastFrameSizeMathces(kFrameWidth, kFrameHeight);
     }
   }
-  EXPECT_NEAR(num_frames_dropped,
-              kDefaultFramerateFps - (kDefaultFramerateFps * 2 / 3),
+  EXPECT_NEAR(num_frames_dropped, max_framerate_ - (max_framerate_ * 2 / 3),
               kErrorMargin);
 
   // Go back up to original mode.
   vie_encoder_->TriggerCpuNormalUsage();
   num_frames_dropped = 0;
-  for (int i = 0; i < kDefaultFramerateFps; ++i) {
+  for (int i = 0; i < max_framerate_; ++i) {
     timestamp_ms += kFrameIntervalMs;
-    fake_clock.AdvanceTimeMicros(kFrameIntervalMs * 1000);
     video_source_.IncomingCapturedFrame(
         CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
-    if (!sink_.WaitForFrame(kFrameTimeoutMs)) {
+    if (!WaitForFrame(kFrameTimeoutMs)) {
       ++num_frames_dropped;
     } else {
       sink_.CheckLastFrameSizeMathces(kFrameWidth, kFrameHeight);
     }
   }
   EXPECT_NEAR(num_frames_dropped, 0, kErrorMargin);
 
   vie_encoder_->Stop();
 }
 
 TEST_F(ViEEncoderTest, DoesntAdaptDownPastMinFramerate) {
   const int kFramerateFps = 5;
   const int kFrameIntervalMs = rtc::kNumMillisecsPerSec / kFramerateFps;
   const int kMinFpsFrameInterval = rtc::kNumMillisecsPerSec / kMinFramerateFps;
   const int kFrameWidth = 1280;
   const int kFrameHeight = 720;
 
-  rtc::ScopedFakeClock fake_clock;
+  // Reconfigure encoder with two temporal layers and screensharing, which will
+  // disable frame dropping and make testing easier.
+  ResetEncoder("VP8", 1, 2, true, true);
+
   vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
   vie_encoder_->SetSource(
       &video_source_,
       VideoSendStream::DegradationPreference::kMaintainResolution);
   video_source_.set_adaptation_enabled(true);
 
-  fake_clock.SetTimeMicros(kFrameIntervalMs * 1000);
-  int64_t timestamp_ms = kFrameIntervalMs;
+  int64_t timestamp_ms = fake_clock_.TimeNanos() / rtc::kNumNanosecsPerMillisec;
 
   // Trigger overuse as much as we can.
   for (int i = 0; i < ViEEncoder::kMaxCpuResolutionDowngrades; ++i) {
     // Insert frames to get a new fps estimate...
     for (int j = 0; j < kFramerateFps; ++j) {
       video_source_.IncomingCapturedFrame(
           CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
       timestamp_ms += kFrameIntervalMs;
-      fake_clock.AdvanceTimeMicros(kFrameIntervalMs * 1000);
     }
     // ...and then try to adapt again.
     vie_encoder_->TriggerCpuOveruse();
   }
 
   // Drain any frame in the pipeline.
-  sink_.WaitForFrame(kDefaultTimeoutMs);
+  WaitForFrame(kDefaultTimeoutMs);
 
   // Insert frames at min fps, all should go through.
   for (int i = 0; i < 10; ++i) {
     timestamp_ms += kMinFpsFrameInterval;
-    fake_clock.AdvanceTimeMicros(kMinFpsFrameInterval * 1000);
     video_source_.IncomingCapturedFrame(
         CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
-    sink_.WaitForEncodedFrame(timestamp_ms);
+    WaitForEncodedFrame(timestamp_ms);
   }
   vie_encoder_->Stop();
 }
+
+TEST_F(ViEEncoderTest, PriodicallyUpdatesChannelParameters) {
+  const int kFrameWidth = 1280;
+  const int kFrameHeight = 720;
+  const int kLowFps = 2;
+  const int kHighFps = 30;
+
+  vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
+
+  int64_t timestamp_ms = fake_clock_.TimeNanos() / rtc::kNumNanosecsPerMillisec;
+  max_framerate_ = kLowFps;
+
+  // Insert 2 seconds of 2fps video.
+  for (int i = 0; i < kLowFps * 2; ++i) {
+    video_source_.IncomingCapturedFrame(
+        CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
+    WaitForEncodedFrame(timestamp_ms);
+    timestamp_ms += 1000 / kLowFps;
+  }
+
+  // Make sure encoder is updated with new target.
+  vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
+  video_source_.IncomingCapturedFrame(
+      CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
+  WaitForEncodedFrame(timestamp_ms);
+  timestamp_ms += 1000 / kLowFps;
+
+  EXPECT_EQ(kLowFps, fake_encoder_.GetConfiguredInputFramerate());
+
+  // Insert 30fps frames for just a little more than the forced update period.
+  const int kVcmTimerIntervalFrames =
+      (vcm::VCMProcessTimer::kDefaultProcessIntervalMs * kHighFps) / 1000;
+  const int kFrameIntervalMs = 1000 / kHighFps;
+  max_framerate_ = kHighFps;
+  for (int i = 0; i < kVcmTimerIntervalFrames + 2; ++i) {
+    video_source_.IncomingCapturedFrame(
+        CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
+    // Wait for encoded frame, but skip ahead if it doesn't arrive as it might
+    // be dropped if the encoder hans't been updated with the new higher target
+    // framerate yet, causing it to overshoot the target bitrate and then
+    // suffering the wrath of the media optimizer.
+    TimedWaitForEncodedFrame(timestamp_ms, 2 * kFrameIntervalMs);
+    timestamp_ms += kFrameIntervalMs;
+  }
+
+  // Don expect correct measurement just yet, but it should be higher than
+  // before.
+  EXPECT_GT(fake_encoder_.GetConfiguredInputFramerate(), kLowFps);
+
+  vie_encoder_->Stop();
+}
 }  // namespace webrtc