Switch reference_less_video_analysis to ABSL_FLAG.

Bug: webrtc:10616
Change-Id: I7b8b1cdae64d8d704056c19806ff8d4708810210
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/143481
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28364}
diff --git a/rtc_tools/BUILD.gn b/rtc_tools/BUILD.gn
index ffade27..c7022b0 100644
--- a/rtc_tools/BUILD.gn
+++ b/rtc_tools/BUILD.gn
@@ -232,13 +232,15 @@
   }
 
   rtc_executable("reference_less_video_analysis") {
+    testonly = true
     sources = [
       "frame_analyzer/reference_less_video_analysis.cc",
     ]
 
     deps = [
-      ":command_line_parser",
       ":reference_less_video_analysis_lib",
+      "//third_party/abseil-cpp/absl/flags:flag",
+      "//third_party/abseil-cpp/absl/flags:parse",
     ]
   }