Reland "Update RTCStatsCollector to work with RtpTransceivers"

Original change's description:
> Update RTCStatsCollector to work with RtpTransceivers
> 
> Bug: webrtc:8764
> Change-Id: I8b442345869eb6d8b65fd12241ed7cb6e7d7ce3d
> Reviewed-on: https://webrtc-review.googlesource.com/49580
> Commit-Queue: Steve Anton <steveanton@webrtc.org>
> Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
> Reviewed-by: Henrik Boström <hbos@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#22026}

Bug: webrtc:8764
Change-Id: I6a682824febf3f4f41397fc1a8dd7396c4ffa8e3
Reviewed-on: https://webrtc-review.googlesource.com/54160
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Commit-Queue: Steve Anton <steveanton@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22064}
diff --git a/pc/trackmediainfomap_unittest.cc b/pc/trackmediainfomap_unittest.cc
index 93d6155..c135564 100644
--- a/pc/trackmediainfomap_unittest.cc
+++ b/pc/trackmediainfomap_unittest.cc
@@ -18,11 +18,11 @@
 
 #include "api/rtpreceiverinterface.h"
 #include "api/rtpsenderinterface.h"
-#include "api/test/mock_rtpreceiver.h"
-#include "api/test/mock_rtpsender.h"
 #include "media/base/mediachannel.h"
 #include "pc/audiotrack.h"
 #include "pc/test/fakevideotracksource.h"
+#include "pc/test/mock_rtpreceiverinternal.h"
+#include "pc/test/mock_rtpsenderinternal.h"
 #include "pc/videotrack.h"
 #include "rtc_base/refcount.h"
 #include "test/gtest.h"
@@ -42,7 +42,7 @@
   return params;
 }
 
-rtc::scoped_refptr<MockRtpSender> CreateMockRtpSender(
+rtc::scoped_refptr<MockRtpSenderInternal> CreateMockRtpSender(
     cricket::MediaType media_type,
     std::initializer_list<uint32_t> ssrcs,
     rtc::scoped_refptr<MediaStreamTrackInterface> track) {
@@ -52,8 +52,8 @@
   } else {
     first_ssrc = 0;
   }
-  rtc::scoped_refptr<MockRtpSender> sender(
-      new rtc::RefCountedObject<MockRtpSender>());
+  rtc::scoped_refptr<MockRtpSenderInternal> sender(
+      new rtc::RefCountedObject<MockRtpSenderInternal>());
   EXPECT_CALL(*sender, track())
       .WillRepeatedly(testing::Return(std::move(track)));
   EXPECT_CALL(*sender, ssrc()).WillRepeatedly(testing::Return(first_ssrc));
@@ -65,12 +65,12 @@
   return sender;
 }
 
-rtc::scoped_refptr<MockRtpReceiver> CreateMockRtpReceiver(
+rtc::scoped_refptr<MockRtpReceiverInternal> CreateMockRtpReceiver(
     cricket::MediaType media_type,
     std::initializer_list<uint32_t> ssrcs,
     rtc::scoped_refptr<MediaStreamTrackInterface> track) {
-  rtc::scoped_refptr<MockRtpReceiver> receiver(
-      new rtc::RefCountedObject<MockRtpReceiver>());
+  rtc::scoped_refptr<MockRtpReceiverInternal> receiver(
+      new rtc::RefCountedObject<MockRtpReceiverInternal>());
   EXPECT_CALL(*receiver, track())
       .WillRepeatedly(testing::Return(std::move(track)));
   EXPECT_CALL(*receiver, media_type())
@@ -108,7 +108,7 @@
 
   void AddRtpSenderWithSsrcs(std::initializer_list<uint32_t> ssrcs,
                              MediaStreamTrackInterface* local_track) {
-    rtc::scoped_refptr<MockRtpSender> rtp_sender = CreateMockRtpSender(
+    rtc::scoped_refptr<MockRtpSenderInternal> rtp_sender = CreateMockRtpSender(
         local_track->kind() == MediaStreamTrackInterface::kAudioKind
             ? cricket::MEDIA_TYPE_AUDIO
             : cricket::MEDIA_TYPE_VIDEO,
@@ -136,7 +136,7 @@
 
   void AddRtpReceiverWithSsrcs(std::initializer_list<uint32_t> ssrcs,
                                MediaStreamTrackInterface* remote_track) {
-    rtc::scoped_refptr<MockRtpReceiver> rtp_receiver = CreateMockRtpReceiver(
+    auto rtp_receiver = CreateMockRtpReceiver(
         remote_track->kind() == MediaStreamTrackInterface::kAudioKind
             ? cricket::MEDIA_TYPE_AUDIO
             : cricket::MEDIA_TYPE_VIDEO,
@@ -173,8 +173,8 @@
  protected:
   cricket::VoiceMediaInfo* voice_media_info_;
   cricket::VideoMediaInfo* video_media_info_;
-  std::vector<rtc::scoped_refptr<RtpSenderInterface>> rtp_senders_;
-  std::vector<rtc::scoped_refptr<RtpReceiverInterface>> rtp_receivers_;
+  std::vector<rtc::scoped_refptr<RtpSenderInternal>> rtp_senders_;
+  std::vector<rtc::scoped_refptr<RtpReceiverInternal>> rtp_receivers_;
   std::unique_ptr<TrackMediaInfoMap> map_;
   rtc::scoped_refptr<AudioTrack> local_audio_track_;
   rtc::scoped_refptr<AudioTrack> remote_audio_track_;