RTCMediaStreamTrackStats.framesReceived collected by RTCStatsCollector.

VideoReceiverInfo::frames_received added based on
VideoReceiveStream::Stats::frame_counts (.key_frames + .delta_frames).

BUG=webrtc:6757, chromium:659137, chromium:627816

Review-Url: https://codereview.webrtc.org/2607913002
Cr-Commit-Position: refs/heads/master@{#16185}
diff --git a/webrtc/api/rtcstatscollector_unittest.cc b/webrtc/api/rtcstatscollector_unittest.cc
index cf6dcf6..83d9fc8 100644
--- a/webrtc/api/rtcstatscollector_unittest.cc
+++ b/webrtc/api/rtcstatscollector_unittest.cc
@@ -1540,6 +1540,7 @@
   video_receiver_info_ssrc3.local_stats[0].ssrc = 3;
   video_receiver_info_ssrc3.frame_width = 6789;
   video_receiver_info_ssrc3.frame_height = 9876;
+  video_receiver_info_ssrc3.frames_received = 2468;
 
   // Remote video track with undefined (default) values
   rtc::scoped_refptr<MediaStreamTrackInterface> remote_video_track_ssrc4 =
@@ -1553,6 +1554,7 @@
   video_receiver_info_ssrc4.local_stats[0].ssrc = 4;
   video_receiver_info_ssrc4.frame_width = 0;
   video_receiver_info_ssrc4.frame_height = 0;
+  video_receiver_info_ssrc4.frames_received = 0;
 
   test_->CreateMockRtpSendersReceiversAndChannels(
       {}, {},
@@ -1625,6 +1627,7 @@
   expected_remote_video_track_ssrc3.detached = false;
   expected_remote_video_track_ssrc3.frame_width = 6789;
   expected_remote_video_track_ssrc3.frame_height = 9876;
+  expected_remote_video_track_ssrc3.frames_received = 2468;
   ASSERT_TRUE(report->Get(expected_remote_video_track_ssrc3.id()));
   EXPECT_EQ(expected_remote_video_track_ssrc3,
             report->Get(expected_remote_video_track_ssrc3.id())->cast_to<
@@ -1638,6 +1641,7 @@
   expected_remote_video_track_ssrc4.remote_source = true;
   expected_remote_video_track_ssrc4.ended = false;
   expected_remote_video_track_ssrc4.detached = false;
+  expected_remote_video_track_ssrc4.frames_received = 0;
   // Should be undefined: |expected_remote_video_track_ssrc4.frame_width| and
   // |expected_remote_video_track_ssrc4.frame_height|.
   ASSERT_TRUE(report->Get(expected_remote_video_track_ssrc4.id()));