Moves VideoAnalyzer class to a separate file.

Bug: wbertc:9510
Change-Id: Id4890a80280a7a16d64b0de03d2bc595d165a7f2
Reviewed-on: https://webrtc-review.googlesource.com/87824
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23903}
diff --git a/video/BUILD.gn b/video/BUILD.gn
index 1b8221e..4cf52a8 100644
--- a/video/BUILD.gn
+++ b/video/BUILD.gn
@@ -155,6 +155,8 @@
       "../api:create_video_quality_test_fixture_api",
     ]
     sources = [
+      "video_analyzer.cc",
+      "video_analyzer.h",
       "video_quality_test.cc",
       "video_quality_test.h",
     ]