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_processing/test/video_processing_unittest.cc

@@ -126,8 +126,6 @@ TEST_F(VideoProcessingTest, Resampler) {
   rewind(source_file_);
   ASSERT_TRUE(source_file_ != NULL) << "Cannot read input file \n";
 
-  // CA not needed here
-  vp_->EnableContentAnalysis(false);
   // no temporal decimation
   vp_->EnableTemporalDecimation(false);