Speculatively re-enable TestVideoQualityVp9

This was reported as flaky. I am unable to reproduce, which could mean
that the issue is fixed, or it could mean that it only flakes on certain
setups (OS, builds, hardware, etc). To aid investigation I am
speculatively re-enabling it; worst case it gets disabled again.

Bug: 993020
Change-Id: I31920b14d1ec02b8cc0eaeb86d93caa8c6226d81
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1762075Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Commit-Queue: Henrik Boström <hbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#688529}

chrome/browser/media/webrtc/webrtc_video_quality_browsertest.cc

@@ -321,14 +321,8 @@ IN_PROC_BROWSER_TEST_P(WebRtcVideoQualityBrowserTest,
   TestVideoQuality("VP8", false /* prefer_hw_video_codec */);
 }
 
-// Fails consistently on Win7 builders.  crbug.com/993020.
-#if defined(OS_WIN)
-#define MAYBE_MANUAL_TestVideoQualityVp9 DISABLED_MANUAL_TestVideoQualityVp9
-#else
-#define MAYBE_MANUAL_TestVideoQualityVp9 MANUAL_TestVideoQualityVp9
-#endif
 IN_PROC_BROWSER_TEST_P(WebRtcVideoQualityBrowserTest,
-                       MAYBE_MANUAL_TestVideoQualityVp9) {
+                       MANUAL_TestVideoQualityVp9) {
   base::ScopedAllowBlockingForTesting allow_blocking;
   TestVideoQuality("VP9", true /* prefer_hw_video_codec */);
 }