Revert "Add option to call VMAF in compare_videos.py."

This reverts commit e307d56bd7e192c354871a739bc0133d88cb5379.

Reason for revert:
Breaks client.webrtc.perf bots. Example failure:
https://ci.chromium.org/buildbot/client.webrtc.perf/Android32%20Tests%20(L%20Nexus7.2)/8635

AttributeError: Values instance has no attribute 'yuv_directory'

Original change's description:
> Add option to call VMAF in compare_videos.py.
> 
> VMAF compares videos on several metrics and produces a unified score.
> 
> Calling it from compare_videos required passing in a path to a VMAF
> directory, where there should be a C++ wrapper executable and a model.
> For now, the relative paths to those are constant.
> 
> VMAF needs to compare aligned videos in YUV format, so two videos
> (ref and test) will be saved by frame_analyzer after it has aligned
> them.
> 
> Bug: webrtc:9642
> Change-Id: Idddfcf6b1b235e7f925696ffc38938fb84c4ff9e
> Reviewed-on: https://webrtc-review.googlesource.com/102140
> Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
> Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
> Commit-Queue: Paulina Hensman <phensman@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#24876}

TBR=phoglund@webrtc.org,sakal@webrtc.org,phensman@webrtc.org

Change-Id: I3e1dc98d7dfc0309ee2934cb3a978eecf274c477
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:9642
Reviewed-on: https://webrtc-review.googlesource.com/102561
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Commit-Queue: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24883}
diff --git a/rtc_tools/frame_analyzer/frame_analyzer.cc b/rtc_tools/frame_analyzer/frame_analyzer.cc
index 56dc1f4..49d381f 100644
--- a/rtc_tools/frame_analyzer/frame_analyzer.cc
+++ b/rtc_tools/frame_analyzer/frame_analyzer.cc
@@ -60,9 +60,6 @@
       " Default: None\n"
       "  - aligned_output_file: Where to write aligned YUV/Y4M output file."
       " If not present, no file will be written."
-      " Default: None\n"
-      "  - yuv_directory: Where to write aligned YUV ref+test output files."
-      " If not present, no files will be written."
       " Default: None\n";
 
   webrtc::test::CommandLineParser parser;
@@ -77,7 +74,6 @@
   parser.SetFlag("reference_file", "ref.yuv");
   parser.SetFlag("test_file", "test.yuv");
   parser.SetFlag("aligned_output_file", "");
-  parser.SetFlag("yuv_directory", "");
   parser.SetFlag("chartjson_result_file", "");
   parser.SetFlag("help", "false");
 
@@ -137,21 +133,14 @@
   if (!chartjson_result_file.empty()) {
     webrtc::test::WritePerfResults(chartjson_result_file);
   }
-  rtc::scoped_refptr<webrtc::test::Video> reordered_video =
-      webrtc::test::GenerateAlignedReferenceVideo(reference_video,
-                                                  matching_indices);
   std::string aligned_output_file = parser.GetFlag("aligned_output_file");
   if (!aligned_output_file.empty()) {
+    rtc::scoped_refptr<webrtc::test::Video> reordered_video =
+        webrtc::test::GenerateAlignedReferenceVideo(reference_video,
+                                                    matching_indices);
     webrtc::test::WriteVideoToFile(reordered_video, aligned_output_file,
                                    /*fps=*/30);
   }
-  std::string yuv_directory = parser.GetFlag("yuv_directory");
-  if (!yuv_directory.empty()) {
-    webrtc::test::WriteVideoToFile(reordered_video, yuv_directory + "ref.yuv",
-                                   /*fps=*/30);
-    webrtc::test::WriteVideoToFile(test_video, yuv_directory + "test.yuv",
-                                   /*fps=*/30);
-  }
 
   return 0;
 }