Remove remaining quality-analysis (QM).

This was never turned on, contains a lot of complexity and somehow
manages triggering a bug in a downstream project.

BUG=webrtc:5066
R=marpan@webrtc.org
TBR=mflodman@webrtc.org

Review URL: https://codereview.webrtc.org/1917323002 .

Cr-Commit-Position: refs/heads/master@{#12692}
diff --git a/webrtc/modules/video_coding/include/video_coding.h b/webrtc/modules/video_coding/include/video_coding.h
index 7d2bdb6..0f85679 100644
--- a/webrtc/modules/video_coding/include/video_coding.h
+++ b/webrtc/modules/video_coding/include/video_coding.h
@@ -31,6 +31,10 @@
 
 class Clock;
 class EncodedImageCallback;
+// TODO(pbos): Remove VCMQMSettingsCallback completely. This might be done by
+// removing the VCM and use VideoSender/VideoReceiver as a public interface
+// directly.
+class VCMQMSettingsCallback;
 class VideoEncoder;
 class VideoDecoder;
 struct CodecSpecificInfo;
@@ -223,7 +227,6 @@
   //                     < 0,    on error.
   virtual int32_t AddVideoFrame(
       const VideoFrame& videoFrame,
-      const VideoContentMetrics* contentMetrics = NULL,
       const CodecSpecificInfo* codecSpecificInfo = NULL) = 0;
 
   // Next frame encoded should be an intra frame (keyframe).