av1: remove I440 placeholders

BUG=aomedia:1672
R=dalecurtis@chromium.org

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I36df0607d647ba7cc4d9c46e70f1a34aaedcc54c
Reviewed-on: https://chromium-review.googlesource.com/999007Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Johann Koenig <johannkoenig@google.com>
Cr-Commit-Position: refs/heads/master@{#548651}

media/filters/aom_video_decoder.cc

@@ -96,13 +96,6 @@ static VideoPixelFormat AomImgFmtToVideoPixelFormat(const aom_image_t* img) {
           return PIXEL_FORMAT_UNKNOWN;
       }
 
-    case AOM_IMG_FMT_I440:
-    case AOM_IMG_FMT_I44016:
-      // TODO(dalecurtis): We'll need to add support for these to handle the
-      // full range of expected AOM content.
-      NOTIMPLEMENTED();
-      break;
-
     default:
       break;
   }