Cleanup of TransportFeedbackObserver interface

The GetTransportFeedbackVector() method is only used in tests, and they
can access the class directly anyway. Keeping it is adding code bloat
and is also making upcoming refactoring more difficult.

Bug: webrtc:8975
Change-Id: I8323addb3c1461dd73b30353c8d9fe9410471c15
Reviewed-on: https://webrtc-review.googlesource.com/60860
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22349}
diff --git a/audio/channel.cc b/audio/channel.cc
index 3472a24..98030c0 100644
--- a/audio/channel.cc
+++ b/audio/channel.cc
@@ -153,10 +153,6 @@
     if (feedback_observer_)
       feedback_observer_->OnTransportFeedback(feedback);
   }
-  std::vector<PacketFeedback> GetTransportFeedbackVector() const override {
-    RTC_NOTREACHED();
-    return std::vector<PacketFeedback>();
-  }
 
  private:
   rtc::CriticalSection crit_;
diff --git a/modules/congestion_controller/include/send_side_congestion_controller.h b/modules/congestion_controller/include/send_side_congestion_controller.h
index 7093da4..5720522 100644
--- a/modules/congestion_controller/include/send_side_congestion_controller.h
+++ b/modules/congestion_controller/include/send_side_congestion_controller.h
@@ -111,7 +111,8 @@
                  size_t length,
                  const PacedPacketInfo& pacing_info) override;
   void OnTransportFeedback(const rtcp::TransportFeedback& feedback) override;
-  std::vector<PacketFeedback> GetTransportFeedbackVector() const override;
+
+  std::vector<PacketFeedback> GetTransportFeedbackVector() const;
 
  private:
   void MaybeTriggerOnNetworkChanged();
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 e3f0c60..c7361af 100644
--- a/modules/congestion_controller/rtp/include/send_side_congestion_controller.h
+++ b/modules/congestion_controller/rtp/include/send_side_congestion_controller.h
@@ -120,7 +120,8 @@
                  size_t length,
                  const PacedPacketInfo& pacing_info) override;
   void OnTransportFeedback(const rtcp::TransportFeedback& feedback) override;
-  std::vector<PacketFeedback> GetTransportFeedbackVector() const override;
+
+  std::vector<PacketFeedback> GetTransportFeedbackVector() const;
 
   // Sets the minimum send bitrate and maximum padding bitrate requested by send
   // streams.
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 fa5d6ab..ea355fb4 100644
--- a/modules/congestion_controller/rtp/send_side_congestion_controller_unittest.cc
+++ b/modules/congestion_controller/rtp/send_side_congestion_controller_unittest.cc
@@ -59,7 +59,9 @@
 class SendSideCongestionControllerTest : public ::testing::Test {
  protected:
   SendSideCongestionControllerTest()
-      : clock_(123456), target_bitrate_observer_(this) {}
+      : clock_(123456),
+        target_bitrate_observer_(this),
+        bandwidth_observer_(nullptr) {}
   ~SendSideCongestionControllerTest() override {}
 
   void SetUp() override {
diff --git a/modules/congestion_controller/send_side_congestion_controller_unittest.cc b/modules/congestion_controller/send_side_congestion_controller_unittest.cc
index eacceb5..754e5b3 100644
--- a/modules/congestion_controller/send_side_congestion_controller_unittest.cc
+++ b/modules/congestion_controller/send_side_congestion_controller_unittest.cc
@@ -47,7 +47,9 @@
 class LegacySendSideCongestionControllerTest : public ::testing::Test {
  protected:
   LegacySendSideCongestionControllerTest()
-      : clock_(123456), target_bitrate_observer_(this) {}
+      : clock_(123456),
+        target_bitrate_observer_(this),
+        bandwidth_observer_(nullptr) {}
   ~LegacySendSideCongestionControllerTest() override {}
 
   void SetUp() override {
diff --git a/modules/rtp_rtcp/include/rtp_rtcp_defines.h b/modules/rtp_rtcp/include/rtp_rtcp_defines.h
index d6730e0..f471ec2 100644
--- a/modules/rtp_rtcp/include/rtp_rtcp_defines.h
+++ b/modules/rtp_rtcp/include/rtp_rtcp_defines.h
@@ -412,8 +412,6 @@
                          const PacedPacketInfo& pacing_info) = 0;
 
   virtual void OnTransportFeedback(const rtcp::TransportFeedback& feedback) = 0;
-
-  virtual std::vector<PacketFeedback> GetTransportFeedbackVector() const = 0;
 };
 
 // Interface for PacketRouter to send rtcp feedback on behalf of