Remove MockRemoteBitrateObserver (unused)

BUG=None

Review-Url: https://codereview.webrtc.org/2731523002
Cr-Original-Commit-Position: refs/heads/master@{#17060}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: fb1fa44d704e9f1dbec7408773c1b0d1a2398e02
diff --git a/audio/audio_send_stream_unittest.cc b/audio/audio_send_stream_unittest.cc
index b1a2401..1a838d8 100644
--- a/audio/audio_send_stream_unittest.cc
+++ b/audio/audio_send_stream_unittest.cc
@@ -21,7 +21,6 @@
 #include "webrtc/modules/congestion_controller/include/congestion_controller.h"
 #include "webrtc/modules/congestion_controller/include/mock/mock_congestion_controller.h"
 #include "webrtc/modules/pacing/paced_sender.h"
-#include "webrtc/modules/remote_bitrate_estimator/include/mock/mock_remote_bitrate_estimator.h"
 #include "webrtc/modules/rtp_rtcp/mocks/mock_rtcp_rtt_stats.h"
 #include "webrtc/test/gtest.h"
 #include "webrtc/test/mock_voe_channel_proxy.h"
@@ -75,7 +74,7 @@
         stream_config_(nullptr),
         congestion_controller_(&simulated_clock_,
                                &bitrate_observer_,
-                               &remote_bitrate_observer_,
+                               nullptr,
                                &event_log_,
                                &packet_router_),
         bitrate_allocator_(&limit_observer_),
@@ -248,7 +247,6 @@
   AudioSendStream::Config stream_config_;
   testing::StrictMock<MockVoEChannelProxy>* channel_proxy_ = nullptr;
   testing::NiceMock<MockCongestionObserver> bitrate_observer_;
-  testing::NiceMock<MockRemoteBitrateObserver> remote_bitrate_observer_;
   MockAudioProcessing audio_processing_;
   MockTransmitMixer transmit_mixer_;
   AudioProcessing::AudioProcessingStatistics audio_processing_stats_;
diff --git a/modules/remote_bitrate_estimator/BUILD.gn b/modules/remote_bitrate_estimator/BUILD.gn
index adfa60c..f4c338a 100644
--- a/modules/remote_bitrate_estimator/BUILD.gn
+++ b/modules/remote_bitrate_estimator/BUILD.gn
@@ -146,7 +146,6 @@
     testonly = true
     sources = [
       "aimd_rate_control_unittest.cc",
-      "include/mock/mock_remote_bitrate_estimator.h",
       "include/mock/mock_remote_bitrate_observer.h",
       "inter_arrival_unittest.cc",
       "overuse_detector_unittest.cc",
diff --git a/modules/remote_bitrate_estimator/include/mock/mock_remote_bitrate_estimator.h b/modules/remote_bitrate_estimator/include/mock/mock_remote_bitrate_estimator.h
deleted file mode 100644
index 8ef645b..0000000
--- a/modules/remote_bitrate_estimator/include/mock/mock_remote_bitrate_estimator.h
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- *  Copyright (c) 2015 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.
- */
-
-#ifndef WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_INCLUDE_MOCK_MOCK_REMOTE_BITRATE_ESTIMATOR_H_
-#define WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_INCLUDE_MOCK_MOCK_REMOTE_BITRATE_ESTIMATOR_H_
-
-#include <vector>
-
-#include "webrtc/modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h"
-#include "webrtc/test/gmock.h"
-
-namespace webrtc {
-
-class MockRemoteBitrateObserver : public RemoteBitrateObserver {
- public:
-  MOCK_METHOD2(OnReceiveBitrateChanged,
-               void(const std::vector<uint32_t>& ssrcs, uint32_t bitrate));
-};
-
-class MockRemoteBitrateEstimator : public RemoteBitrateEstimator {
- public:
-  MOCK_METHOD3(IncomingPacket, void(int64_t, size_t, const RTPHeader&));
-  MOCK_METHOD1(RemoveStream, void(uint32_t));
-  MOCK_CONST_METHOD2(LatestEstimate, bool(std::vector<uint32_t>*, uint32_t*));
-
-  // From CallStatsObserver;
-  MOCK_METHOD2(OnRttUpdate, void(int64_t, int64_t));
-
-  // From Module.
-  MOCK_METHOD0(TimeUntilNextProcess, int64_t());
-  MOCK_METHOD0(Process, void());
-  MOCK_METHOD1(SetMinBitrate, void(int));
-};
-
-}  // namespace webrtc
-
-#endif  // WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_INCLUDE_MOCK_MOCK_REMOTE_BITRATE_ESTIMATOR_H_
diff --git a/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.cc b/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.cc
index 094bf0d..7b4cc2b 100644
--- a/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.cc
+++ b/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.cc
@@ -57,7 +57,6 @@
       last_process_time_(-1),
       process_interval_ms_(kProcessIntervalMs),
       uma_recorded_(false) {
-  assert(observer_);
   LOG(LS_INFO) << "RemoteBitrateEstimatorSingleStream: Instantiating.";
 }
 
@@ -201,7 +200,8 @@
     RTC_DCHECK_GT(process_interval_ms_, 0);
     std::vector<uint32_t> ssrcs;
     GetSsrcs(&ssrcs);
-    observer_->OnReceiveBitrateChanged(ssrcs, target_bitrate);
+    if (observer_)
+      observer_->OnReceiveBitrateChanged(ssrcs, target_bitrate);
   }
 }
 
diff --git a/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h b/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h
index 31d7962..b893f56 100644
--- a/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h
+++ b/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h
@@ -56,12 +56,12 @@
   // otherwise creates it.
   AimdRateControl* GetRemoteRate() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_.get());
 
-  Clock* clock_;
+  Clock* const clock_;
   SsrcOveruseEstimatorMap overuse_detectors_ GUARDED_BY(crit_sect_.get());
   RateStatistics incoming_bitrate_ GUARDED_BY(crit_sect_.get());
   uint32_t last_valid_incoming_bitrate_ GUARDED_BY(crit_sect_.get());
   std::unique_ptr<AimdRateControl> remote_rate_ GUARDED_BY(crit_sect_.get());
-  RemoteBitrateObserver* observer_ GUARDED_BY(crit_sect_.get());
+  RemoteBitrateObserver* const observer_ GUARDED_BY(crit_sect_.get());
   std::unique_ptr<CriticalSectionWrapper> crit_sect_;
   int64_t last_process_time_;
   int64_t process_interval_ms_ GUARDED_BY(crit_sect_.get());