diff --git a/modules/congestion_controller/rtp/acknowledged_bitrate_estimator.cc b/modules/congestion_controller/rtp/acknowledged_bitrate_estimator.cc
index 8858b6eed6..55cd176a83 100644
--- a/modules/congestion_controller/rtp/acknowledged_bitrate_estimator.cc
+++ b/modules/congestion_controller/rtp/acknowledged_bitrate_estimator.cc
@@ -17,6 +17,7 @@
 #include "rtc_base/ptr_util.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
 bool IsInSendTimeHistory(const PacketFeedback& packet) {
@@ -64,4 +65,5 @@ void AcknowledgedBitrateEstimator::MaybeExpectFastRateChange(
   }
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/acknowledged_bitrate_estimator.h b/modules/congestion_controller/rtp/acknowledged_bitrate_estimator.h
index 2d57ec82fb..7fbd3ed821 100644
--- a/modules/congestion_controller/rtp/acknowledged_bitrate_estimator.h
+++ b/modules/congestion_controller/rtp/acknowledged_bitrate_estimator.h
@@ -21,6 +21,8 @@ namespace webrtc {
 
 struct PacketFeedback;
 
+namespace webrtc_cc {
+
 class AcknowledgedBitrateEstimator {
  public:
   explicit AcknowledgedBitrateEstimator(
@@ -40,6 +42,7 @@ class AcknowledgedBitrateEstimator {
   std::unique_ptr<BitrateEstimator> bitrate_estimator_;
 };
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_ACKNOWLEDGED_BITRATE_ESTIMATOR_H_
diff --git a/modules/congestion_controller/rtp/acknowledged_bitrate_estimator_unittest.cc b/modules/congestion_controller/rtp/acknowledged_bitrate_estimator_unittest.cc
index c7720a85ca..5c81cf2ac3 100644
--- a/modules/congestion_controller/rtp/acknowledged_bitrate_estimator_unittest.cc
+++ b/modules/congestion_controller/rtp/acknowledged_bitrate_estimator_unittest.cc
@@ -24,6 +24,7 @@ using testing::InSequence;
 using testing::Return;
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
 
@@ -131,4 +132,5 @@ TEST(TestAcknowledgedBitrateEstimator, ReturnBitrate) {
   EXPECT_EQ(return_value, states.acknowledged_bitrate_estimator->bitrate_bps());
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc*/
diff --git a/modules/congestion_controller/rtp/alr_detector.cc b/modules/congestion_controller/rtp/alr_detector.cc
index 2a36d551f3..30d89d1312 100644
--- a/modules/congestion_controller/rtp/alr_detector.cc
+++ b/modules/congestion_controller/rtp/alr_detector.cc
@@ -25,6 +25,7 @@
 #include "system_wrappers/include/field_trial.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 AlrDetector::AlrDetector() : AlrDetector(nullptr) {}
 
 AlrDetector::AlrDetector(RtcEventLog* event_log)
@@ -92,4 +93,5 @@ rtc::Optional<int64_t> AlrDetector::GetApplicationLimitedRegionStartTime()
     const {
   return alr_started_time_ms_;
 }
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/alr_detector.h b/modules/congestion_controller/rtp/alr_detector.h
index dc609280ca..270fb2e77b 100644
--- a/modules/congestion_controller/rtp/alr_detector.h
+++ b/modules/congestion_controller/rtp/alr_detector.h
@@ -22,6 +22,8 @@ namespace webrtc {
 
 class RtcEventLog;
 
+namespace webrtc_cc {
+
 // Application limited region detector is a class that utilizes signals of
 // elapsed time and bytes sent to estimate whether network traffic is
 // currently limited by the application's ability to generate traffic.
@@ -69,6 +71,7 @@ class AlrDetector {
   RtcEventLog* event_log_;
 };
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_ALR_DETECTOR_H_
diff --git a/modules/congestion_controller/rtp/alr_detector_unittest.cc b/modules/congestion_controller/rtp/alr_detector_unittest.cc
index 82ad4d6252..d5420d3954 100644
--- a/modules/congestion_controller/rtp/alr_detector_unittest.cc
+++ b/modules/congestion_controller/rtp/alr_detector_unittest.cc
@@ -21,6 +21,7 @@ constexpr int kEstimatedBitrateBps = 300000;
 }  // namespace
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
 class SimulateOutgoingTrafficIn {
@@ -172,4 +173,5 @@ TEST_F(AlrDetectorTest, ParseActiveFieldTrial) {
   EXPECT_EQ(1, parsed_params->group_id);
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/bitrate_estimator.cc b/modules/congestion_controller/rtp/bitrate_estimator.cc
index e682e64fde..2b28ac558d 100644
--- a/modules/congestion_controller/rtp/bitrate_estimator.cc
+++ b/modules/congestion_controller/rtp/bitrate_estimator.cc
@@ -16,6 +16,7 @@
 #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
 constexpr int kInitialRateWindowMs = 500;
@@ -104,4 +105,5 @@ void BitrateEstimator::ExpectFastRateChange() {
   bitrate_estimate_var_ += 200;
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/bitrate_estimator.h b/modules/congestion_controller/rtp/bitrate_estimator.h
index 17ad8772e2..1704d3f93e 100644
--- a/modules/congestion_controller/rtp/bitrate_estimator.h
+++ b/modules/congestion_controller/rtp/bitrate_estimator.h
@@ -16,6 +16,7 @@
 #include "api/optional.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 // Computes a bayesian estimate of the throughput given acks containing
 // the arrival time and payload size. Samples which are far from the current
@@ -41,6 +42,7 @@ class BitrateEstimator {
   float bitrate_estimate_var_;
 };
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_BITRATE_ESTIMATOR_H_
diff --git a/modules/congestion_controller/rtp/congestion_controller_unittests_helper.cc b/modules/congestion_controller/rtp/congestion_controller_unittests_helper.cc
index f2b4467dd7..2f52799bb0 100644
--- a/modules/congestion_controller/rtp/congestion_controller_unittests_helper.cc
+++ b/modules/congestion_controller/rtp/congestion_controller_unittests_helper.cc
@@ -14,6 +14,7 @@
 #include "test/gtest.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 void ComparePacketFeedbackVectors(const std::vector<PacketFeedback>& truth,
                                   const std::vector<PacketFeedback>& input) {
   ASSERT_EQ(truth.size(), input.size());
@@ -39,4 +40,5 @@ void ComparePacketFeedbackVectors(const std::vector<PacketFeedback>& truth,
     EXPECT_EQ(truth[i].pacing_info, input[i].pacing_info);
   }
 }
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/congestion_controller_unittests_helper.h b/modules/congestion_controller/rtp/congestion_controller_unittests_helper.h
index 98dfb3ddce..9bf28148f1 100644
--- a/modules/congestion_controller/rtp/congestion_controller_unittests_helper.h
+++ b/modules/congestion_controller/rtp/congestion_controller_unittests_helper.h
@@ -16,8 +16,10 @@
 #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 void ComparePacketFeedbackVectors(const std::vector<PacketFeedback>& truth,
                                   const std::vector<PacketFeedback>& input);
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_CONGESTION_CONTROLLER_UNITTESTS_HELPER_H_
diff --git a/modules/congestion_controller/rtp/delay_based_bwe.cc b/modules/congestion_controller/rtp/delay_based_bwe.cc
index 71567f7be3..d5256288a6 100644
--- a/modules/congestion_controller/rtp/delay_based_bwe.cc
+++ b/modules/congestion_controller/rtp/delay_based_bwe.cc
@@ -70,6 +70,7 @@ size_t ReadTrendlineFilterWindowSize() {
 }  // namespace
 
 namespace webrtc {
+namespace webrtc_cc {
 
 DelayBasedBwe::Result::Result()
     : updated(false),
@@ -326,4 +327,5 @@ void DelayBasedBwe::SetMinBitrate(int min_bitrate_bps) {
 int64_t DelayBasedBwe::GetExpectedBwePeriodMs() const {
   return rate_control_.GetExpectedBandwidthPeriodMs();
 }
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/delay_based_bwe.h b/modules/congestion_controller/rtp/delay_based_bwe.h
index 1e8c0685f1..43bc92bfe1 100644
--- a/modules/congestion_controller/rtp/delay_based_bwe.h
+++ b/modules/congestion_controller/rtp/delay_based_bwe.h
@@ -28,6 +28,8 @@ namespace webrtc {
 
 class RtcEventLog;
 
+namespace webrtc_cc {
+
 class DelayBasedBwe {
  public:
   static const int64_t kStreamTimeOutMs = 2000;
@@ -87,6 +89,7 @@ class DelayBasedBwe {
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(DelayBasedBwe);
 };
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_DELAY_BASED_BWE_H_
diff --git a/modules/congestion_controller/rtp/delay_based_bwe_unittest.cc b/modules/congestion_controller/rtp/delay_based_bwe_unittest.cc
index b30ad4ccf8..339d8452f3 100644
--- a/modules/congestion_controller/rtp/delay_based_bwe_unittest.cc
+++ b/modules/congestion_controller/rtp/delay_based_bwe_unittest.cc
@@ -17,6 +17,7 @@
 #include "test/gtest.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
 constexpr int kNumProbesCluster0 = 5;
@@ -234,4 +235,5 @@ TEST_F(DelayBasedBweTest, TestInitialOveruse) {
   EXPECT_NEAR(bitrate_observer_.latest_bitrate(), kStartBitrate / 2, 15000);
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/delay_based_bwe_unittest_helper.cc b/modules/congestion_controller/rtp/delay_based_bwe_unittest_helper.cc
index 7128371012..c306e66d6c 100644
--- a/modules/congestion_controller/rtp/delay_based_bwe_unittest_helper.cc
+++ b/modules/congestion_controller/rtp/delay_based_bwe_unittest_helper.cc
@@ -18,6 +18,7 @@
 #include "rtc_base/ptr_util.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 constexpr size_t kMtu = 1200;
 constexpr uint32_t kAcceptedBitrateErrorBps = 50000;
@@ -512,4 +513,5 @@ void DelayBasedBweTest::TestWrappingHelper(int silence_time_s) {
   bitrate_estimator_->LatestEstimate(&ssrcs, &bitrate_after);
   EXPECT_LT(bitrate_after, bitrate_before);
 }
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/delay_based_bwe_unittest_helper.h b/modules/congestion_controller/rtp/delay_based_bwe_unittest_helper.h
index 19fbb78e88..8658d0292a 100644
--- a/modules/congestion_controller/rtp/delay_based_bwe_unittest_helper.h
+++ b/modules/congestion_controller/rtp/delay_based_bwe_unittest_helper.h
@@ -25,6 +25,7 @@
 #include "test/gtest.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 namespace test {
 
 class TestBitrateObserver : public RemoteBitrateObserver {
@@ -173,6 +174,7 @@ class DelayBasedBweTest : public ::testing::Test {
 
   RTC_DISALLOW_COPY_AND_ASSIGN(DelayBasedBweTest);
 };
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_DELAY_BASED_BWE_UNITTEST_HELPER_H_
diff --git a/modules/congestion_controller/rtp/delay_increase_detector_interface.h b/modules/congestion_controller/rtp/delay_increase_detector_interface.h
index 4df7148206..d8a3647f9f 100644
--- a/modules/congestion_controller/rtp/delay_increase_detector_interface.h
+++ b/modules/congestion_controller/rtp/delay_increase_detector_interface.h
@@ -16,6 +16,7 @@
 #include "rtc_base/constructormagic.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 class DelayIncreaseDetectorInterface {
  public:
@@ -32,6 +33,7 @@ class DelayIncreaseDetectorInterface {
 
   RTC_DISALLOW_COPY_AND_ASSIGN(DelayIncreaseDetectorInterface);
 };
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_DELAY_INCREASE_DETECTOR_INTERFACE_H_
diff --git a/modules/congestion_controller/rtp/goog_cc_network_control.cc b/modules/congestion_controller/rtp/goog_cc_network_control.cc
index 203c3d3246..7627b569fa 100644
--- a/modules/congestion_controller/rtp/goog_cc_network_control.cc
+++ b/modules/congestion_controller/rtp/goog_cc_network_control.cc
@@ -32,6 +32,7 @@
 #include "system_wrappers/include/field_trial.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 namespace {
 
 const char kCwndExperiment[] = "WebRTC-CwndExperiment";
@@ -422,4 +423,5 @@ void GoogCcNetworkController::UpdatePacingRates(Timestamp at_time) {
   observer_->OnPacerConfig(msg);
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/goog_cc_network_control.h b/modules/congestion_controller/rtp/goog_cc_network_control.h
index 80d534f78c..0029474edd 100644
--- a/modules/congestion_controller/rtp/goog_cc_network_control.h
+++ b/modules/congestion_controller/rtp/goog_cc_network_control.h
@@ -27,6 +27,7 @@
 #include "rtc_base/constructormagic.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 class GoogCcNetworkController : public NetworkControllerInterface {
  public:
@@ -87,6 +88,7 @@ class GoogCcNetworkController : public NetworkControllerInterface {
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(GoogCcNetworkController);
 };
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_GOOG_CC_NETWORK_CONTROL_H_
diff --git a/modules/congestion_controller/rtp/include/send_side_congestion_controller.h b/modules/congestion_controller/rtp/include/send_side_congestion_controller.h
index a941fd2d15..d3a93d574f 100644
--- a/modules/congestion_controller/rtp/include/send_side_congestion_controller.h
+++ b/modules/congestion_controller/rtp/include/send_side_congestion_controller.h
@@ -42,6 +42,8 @@ class Clock;
 class RateLimiter;
 class RtcEventLog;
 
+namespace webrtc_cc {
+
 namespace send_side_cc_internal {
 // This is used to observe the network controller state and route calls to
 // the proper handler. It also keeps cached values for safe asynchronous use.
@@ -191,6 +193,7 @@ class SendSideCongestionController : public CallStatsObserver,
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(SendSideCongestionController);
 };
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_INCLUDE_SEND_SIDE_CONGESTION_CONTROLLER_H_
diff --git a/modules/congestion_controller/rtp/median_slope_estimator.cc b/modules/congestion_controller/rtp/median_slope_estimator.cc
index 31b429ab9d..2c025cc31d 100644
--- a/modules/congestion_controller/rtp/median_slope_estimator.cc
+++ b/modules/congestion_controller/rtp/median_slope_estimator.cc
@@ -18,6 +18,7 @@
 #include "rtc_base/logging.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 constexpr unsigned int kDeltaCounterMax = 1000;
 
@@ -90,4 +91,5 @@ void MedianSlopeEstimator::Update(double recv_delta_ms,
   BWE_TEST_LOGGING_PLOT(1, "trendline_slope", arrival_time_ms, trendline_);
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/median_slope_estimator.h b/modules/congestion_controller/rtp/median_slope_estimator.h
index f7f2570dab..3dd3c21c9f 100644
--- a/modules/congestion_controller/rtp/median_slope_estimator.h
+++ b/modules/congestion_controller/rtp/median_slope_estimator.h
@@ -20,6 +20,7 @@
 #include "rtc_base/numerics/percentile_filter.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 class MedianSlopeEstimator {
  public:
@@ -67,6 +68,7 @@ class MedianSlopeEstimator {
 
   RTC_DISALLOW_COPY_AND_ASSIGN(MedianSlopeEstimator);
 };
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_MEDIAN_SLOPE_ESTIMATOR_H_
diff --git a/modules/congestion_controller/rtp/median_slope_estimator_unittest.cc b/modules/congestion_controller/rtp/median_slope_estimator_unittest.cc
index 2e243879ae..7e5e90426c 100644
--- a/modules/congestion_controller/rtp/median_slope_estimator_unittest.cc
+++ b/modules/congestion_controller/rtp/median_slope_estimator_unittest.cc
@@ -13,6 +13,7 @@
 #include "test/gtest.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
 constexpr size_t kWindowSize = 20;
@@ -69,4 +70,5 @@ TEST(MedianSlopeEstimator, JitteryLineSlopeZero) {
   TestEstimator(0, kAvgTimeBetweenPackets / 3.0, 0.02);
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/pacer_controller.cc b/modules/congestion_controller/rtp/pacer_controller.cc
index 69d47b60ef..2af24feac7 100644
--- a/modules/congestion_controller/rtp/pacer_controller.cc
+++ b/modules/congestion_controller/rtp/pacer_controller.cc
@@ -15,6 +15,7 @@
 #include "rtc_base/logging.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 PacerController::PacerController(PacedSender* pacer) : pacer_(pacer) {
   sequenced_checker_.Detach();
@@ -80,4 +81,5 @@ void PacerController::SetPacerState(bool paused) {
   pacer_paused_ = paused;
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/pacer_controller.h b/modules/congestion_controller/rtp/pacer_controller.h
index 68d0bc03e3..eb0e4a00cf 100644
--- a/modules/congestion_controller/rtp/pacer_controller.h
+++ b/modules/congestion_controller/rtp/pacer_controller.h
@@ -20,6 +20,8 @@
 namespace webrtc {
 class Clock;
 
+namespace webrtc_cc {
+
 // Wrapper class to control pacer using task queues. Note that this class is
 // only designed to be used from a single task queue and has no built in
 // concurrency safety.
@@ -49,5 +51,6 @@ class PacerController {
   rtc::SequencedTaskChecker sequenced_checker_;
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(PacerController);
 };
+}  // namespace webrtc_cc
 }  // namespace webrtc
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_PACER_CONTROLLER_H_
diff --git a/modules/congestion_controller/rtp/probe_bitrate_estimator.cc b/modules/congestion_controller/rtp/probe_bitrate_estimator.cc
index a7bfa41ca7..f091aec6df 100644
--- a/modules/congestion_controller/rtp/probe_bitrate_estimator.cc
+++ b/modules/congestion_controller/rtp/probe_bitrate_estimator.cc
@@ -53,6 +53,7 @@ constexpr int kMaxProbeIntervalMs = 1000;
 }  // namespace
 
 namespace webrtc {
+namespace webrtc_cc {
 
 ProbeBitrateEstimator::ProbeBitrateEstimator(RtcEventLog* event_log)
     : event_log_(event_log) {}
@@ -186,4 +187,5 @@ void ProbeBitrateEstimator::EraseOldClusters(int64_t timestamp_ms) {
     }
   }
 }
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/probe_bitrate_estimator.h b/modules/congestion_controller/rtp/probe_bitrate_estimator.h
index 481cac637e..96eca0aa2b 100644
--- a/modules/congestion_controller/rtp/probe_bitrate_estimator.h
+++ b/modules/congestion_controller/rtp/probe_bitrate_estimator.h
@@ -18,6 +18,7 @@
 
 namespace webrtc {
 class RtcEventLog;
+namespace webrtc_cc {
 
 class ProbeBitrateEstimator {
  public:
@@ -50,6 +51,7 @@ class ProbeBitrateEstimator {
   rtc::Optional<int> estimated_bitrate_bps_;
 };
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_PROBE_BITRATE_ESTIMATOR_H_
diff --git a/modules/congestion_controller/rtp/probe_bitrate_estimator_unittest.cc b/modules/congestion_controller/rtp/probe_bitrate_estimator_unittest.cc
index 66645aa134..a45bf822fb 100644
--- a/modules/congestion_controller/rtp/probe_bitrate_estimator_unittest.cc
+++ b/modules/congestion_controller/rtp/probe_bitrate_estimator_unittest.cc
@@ -18,6 +18,7 @@
 #include "test/gtest.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
 constexpr int kInvalidBitrate = -1;
@@ -218,4 +219,5 @@ TEST_F(TestProbeBitrateEstimator, FetchLastEstimatedBitrateBps) {
   EXPECT_FALSE(probe_bitrate_estimator_.FetchAndResetLastEstimatedBitrateBps());
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/probe_controller.cc b/modules/congestion_controller/rtp/probe_controller.cc
index 6bac270829..863524d064 100644
--- a/modules/congestion_controller/rtp/probe_controller.cc
+++ b/modules/congestion_controller/rtp/probe_controller.cc
@@ -19,6 +19,7 @@
 #include "system_wrappers/include/metrics.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
 // The minimum number probing packets used.
@@ -305,4 +306,5 @@ void ProbeController::InitiateProbing(
   }
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/probe_controller.h b/modules/congestion_controller/rtp/probe_controller.h
index 2becd3025e..f44c06ea2e 100644
--- a/modules/congestion_controller/rtp/probe_controller.h
+++ b/modules/congestion_controller/rtp/probe_controller.h
@@ -22,6 +22,8 @@ namespace webrtc {
 
 class Clock;
 
+namespace webrtc_cc {
+
 // This class controls initiation of probing to estimate initial channel
 // capacity. There is also support for probing during a session when max
 // bitrate is adjusted by an application.
@@ -92,6 +94,7 @@ class ProbeController {
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(ProbeController);
 };
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_PROBE_CONTROLLER_H_
diff --git a/modules/congestion_controller/rtp/probe_controller_unittest.cc b/modules/congestion_controller/rtp/probe_controller_unittest.cc
index 4634ea8fae..0193747912 100644
--- a/modules/congestion_controller/rtp/probe_controller_unittest.cc
+++ b/modules/congestion_controller/rtp/probe_controller_unittest.cc
@@ -26,6 +26,7 @@ using testing::Return;
 using webrtc::ProbeClusterConfig;
 
 namespace webrtc {
+namespace webrtc_cc {
 namespace test {
 
 namespace {
@@ -289,4 +290,5 @@ TEST_F(ProbeControllerTest, TestExponentialProbingOverflow) {
 }
 
 }  // namespace test
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/send_side_congestion_controller.cc b/modules/congestion_controller/rtp/send_side_congestion_controller.cc
index 7606722efe..b2e7069fe8 100644
--- a/modules/congestion_controller/rtp/send_side_congestion_controller.cc
+++ b/modules/congestion_controller/rtp/send_side_congestion_controller.cc
@@ -34,6 +34,7 @@
 using rtc::MakeUnique;
 
 namespace webrtc {
+namespace webrtc_cc {
 namespace {
 
 static const int64_t kRetransmitWindowSizeMs = 500;
@@ -658,4 +659,5 @@ void SendSideCongestionController::OnReceivedRtcpReceiverReportBlocks(
       [this, msg]() { controller_->OnTransportLossReport(msg); });
   last_report_block_time_ = now;
 }
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/send_side_congestion_controller_unittest.cc b/modules/congestion_controller/rtp/send_side_congestion_controller_unittest.cc
index 896cd76b5d..ea8479fda1 100644
--- a/modules/congestion_controller/rtp/send_side_congestion_controller_unittest.cc
+++ b/modules/congestion_controller/rtp/send_side_congestion_controller_unittest.cc
@@ -32,6 +32,7 @@ using testing::SaveArg;
 using testing::StrictMock;
 
 namespace webrtc {
+namespace webrtc_cc {
 namespace test {
 
 namespace {
@@ -515,4 +516,5 @@ TEST_F(SendSideCongestionControllerTest, PacerQueueEncodeRatePushback) {
 }
 
 }  // namespace test
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/send_time_history.cc b/modules/congestion_controller/rtp/send_time_history.cc
index 74b9c66a10..b0619a2595 100644
--- a/modules/congestion_controller/rtp/send_time_history.cc
+++ b/modules/congestion_controller/rtp/send_time_history.cc
@@ -18,6 +18,7 @@
 #include "system_wrappers/include/clock.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 SendTimeHistory::SendTimeHistory(const Clock* clock,
                                  int64_t packet_age_limit_ms)
@@ -100,4 +101,5 @@ size_t SendTimeHistory::GetOutstandingBytes(uint16_t local_net_id,
   return outstanding_bytes;
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/send_time_history.h b/modules/congestion_controller/rtp/send_time_history.h
index d1a2a65603..96b1271953 100644
--- a/modules/congestion_controller/rtp/send_time_history.h
+++ b/modules/congestion_controller/rtp/send_time_history.h
@@ -20,6 +20,7 @@
 namespace webrtc {
 class Clock;
 struct PacketFeedback;
+namespace webrtc_cc {
 
 class SendTimeHistory {
  public:
@@ -54,5 +55,6 @@ class SendTimeHistory {
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(SendTimeHistory);
 };
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_SEND_TIME_HISTORY_H_
diff --git a/modules/congestion_controller/rtp/send_time_history_unittest.cc b/modules/congestion_controller/rtp/send_time_history_unittest.cc
index 3e852ba631..5ad1015ed1 100644
--- a/modules/congestion_controller/rtp/send_time_history_unittest.cc
+++ b/modules/congestion_controller/rtp/send_time_history_unittest.cc
@@ -19,6 +19,7 @@
 #include "test/gtest.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 namespace test {
 
 static const int kDefaultHistoryLengthMs = 1000;
@@ -253,4 +254,5 @@ TEST_F(SendTimeHistoryTest, InterlievedGetAndRemove) {
   EXPECT_EQ(packets[2], packet3);
 }
 }  // namespace test
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/transport_feedback_adapter.cc b/modules/congestion_controller/rtp/transport_feedback_adapter.cc
index 5537c32e8a..d7c7bf9e2a 100644
--- a/modules/congestion_controller/rtp/transport_feedback_adapter.cc
+++ b/modules/congestion_controller/rtp/transport_feedback_adapter.cc
@@ -19,6 +19,7 @@
 #include "rtc_base/numerics/mod_ops.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 const int64_t kNoTimestamp = -1;
 const int64_t kSendTimeHistoryWindowMs = 60000;
@@ -188,4 +189,5 @@ size_t TransportFeedbackAdapter::GetOutstandingBytes() const {
   rtc::CritScope cs(&lock_);
   return send_time_history_.GetOutstandingBytes(local_net_id_, remote_net_id_);
 }
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/transport_feedback_adapter.h b/modules/congestion_controller/rtp/transport_feedback_adapter.h
index abb9abe4d2..67c00f5eac 100644
--- a/modules/congestion_controller/rtp/transport_feedback_adapter.h
+++ b/modules/congestion_controller/rtp/transport_feedback_adapter.h
@@ -28,6 +28,7 @@ namespace rtcp {
 class TransportFeedback;
 }  // namespace rtcp
 
+namespace webrtc_cc {
 class TransportFeedbackAdapter {
  public:
   explicit TransportFeedbackAdapter(const Clock* clock);
@@ -73,6 +74,7 @@ class TransportFeedbackAdapter {
       RTC_GUARDED_BY(&observers_lock_);
 };
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_TRANSPORT_FEEDBACK_ADAPTER_H_
diff --git a/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc b/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc
index f115c8c545..e62fc95275 100644
--- a/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc
+++ b/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc
@@ -27,6 +27,7 @@ using ::testing::_;
 using ::testing::Invoke;
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
 const PacedPacketInfo kPacingInfo0(0, 5, 2000);
@@ -388,4 +389,5 @@ TEST_F(TransportFeedbackAdapterTest, TimestampDeltas) {
   }
 }
 }  // namespace test
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/trendline_estimator.cc b/modules/congestion_controller/rtp/trendline_estimator.cc
index 1d27b2aa42..1c07e5ca2d 100644
--- a/modules/congestion_controller/rtp/trendline_estimator.cc
+++ b/modules/congestion_controller/rtp/trendline_estimator.cc
@@ -20,6 +20,7 @@
 #include "rtc_base/numerics/safe_minmax.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
 rtc::Optional<double> LinearFitSlope(
@@ -180,4 +181,5 @@ void TrendlineEstimator::UpdateThreshold(double modified_offset,
   last_update_ms_ = now_ms;
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/trendline_estimator.h b/modules/congestion_controller/rtp/trendline_estimator.h
index 17befadb6c..7628fbc1e5 100644
--- a/modules/congestion_controller/rtp/trendline_estimator.h
+++ b/modules/congestion_controller/rtp/trendline_estimator.h
@@ -20,6 +20,7 @@
 #include "rtc_base/constructormagic.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 class TrendlineEstimator : public DelayIncreaseDetectorInterface {
  public:
@@ -87,6 +88,7 @@ class TrendlineEstimator : public DelayIncreaseDetectorInterface {
 
   RTC_DISALLOW_COPY_AND_ASSIGN(TrendlineEstimator);
 };
+}  // namespace webrtc_cc
 }  // namespace webrtc
 
 #endif  // MODULES_CONGESTION_CONTROLLER_RTP_TRENDLINE_ESTIMATOR_H_
diff --git a/modules/congestion_controller/rtp/trendline_estimator_unittest.cc b/modules/congestion_controller/rtp/trendline_estimator_unittest.cc
index 6a765caf52..737b7b48de 100644
--- a/modules/congestion_controller/rtp/trendline_estimator_unittest.cc
+++ b/modules/congestion_controller/rtp/trendline_estimator_unittest.cc
@@ -13,6 +13,7 @@
 #include "test/gtest.h"
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
 constexpr size_t kWindowSize = 20;
@@ -70,4 +71,5 @@ TEST(TrendlineEstimator, JitteryLineSlopeZero) {
   TestEstimator(0, kAvgTimeBetweenPackets / 3.0, 0.02);
 }
 
+}  // namespace webrtc_cc
 }  // namespace webrtc