Sheriff: Comment out broken test

The MediaColorTest is failing on ChromeOS.

https://crbug.com/938618

Bug: 938618

TBR: timvolodine@chromium.org
Change-Id: I59db4abec0b91b0a3f93687b2face2babcd4b5fc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1504260Reviewed-by: Peter Williamson <petewil@chromium.org>
Commit-Queue: Peter Williamson <petewil@chromium.org>
Auto-Submit: Peter Williamson <petewil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#637902}

content/browser/media/media_color_browsertest.cc

@@ -52,8 +52,10 @@ IN_PROC_BROWSER_TEST_F(MediaColorTest, Yuv444pVp9) {
 }
 
 #if BUILDFLAG(USE_PROPRIETARY_CODECS)
+
 // This test fails on Android: http://crbug.com/938320
-#if defined(OS_ANDROID)
+// It also fails on ChromeOS https://crbug.com/938618
+#if defined(OS_ANDROID) || defined(OS_CHROMEOS)
 #define MAYBE_Yuv420pH264 DISABLED_Yuv420pH264
 #else
 #define MAYBE_Yuv420pH264 Yuv420pH264