Update comment for why Hi10p is disabled in VTVDA.

BUG=none
TEST=none
R=sandersd

Change-Id: I1f85e8ce594e4b0cf26d8d699d668fad3cf82796
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1679474
Auto-Submit: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672709}

media/gpu/mac/vt_video_decode_accelerator_mac.cc

@@ -58,11 +58,14 @@ const VideoCodecProfile kSupportedProfiles[] = {
     H264PROFILE_BASELINE, H264PROFILE_EXTENDED, H264PROFILE_MAIN,
     H264PROFILE_HIGH,
 
-    // TODO(hubbe): Re-enable this once software fallback is working.
-    // http://crbug.com/605790
+    // TODO(sandersd): Hi10p fails during
+    // CMVideoFormatDescriptionCreateFromH264ParameterSets with
+    // kCMFormatDescriptionError_InvalidParameter.
+    //
     // H264PROFILE_HIGH10PROFILE,
 
     // TODO(sandersd): Find and test media with these profiles before enabling.
+    //
     // H264PROFILE_SCALABLEBASELINE,
     // H264PROFILE_SCALABLEHIGH,
     // H264PROFILE_STEREOHIGH,