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}

webrtc/modules/video_coding/include/video_coding.h

@@ -31,6 +31,10 @@ namespace webrtc {
 
 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 @@ class VideoCodingModule : public Module {
   //                     < 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).