Roll src/third_party/libavif/src/ 50c5bbd8f..4cfee6282 (13 commits)

https://chromium.googlesource.com/external/github.com/AOMediaCodec/libavif.git/+log/50c5bbd8f04a..4cfee6282b97

$ git log 50c5bbd8f..4cfee6282 --date=short --no-merges --format='%ad %ae %s'
2020-08-10 ccom Add AVIF_FMT_ZU to fix compiling with non-standard/old compilers (#260)
2020-08-10 wtc Fail if a tile is completely outside grid bounds
2020-08-10 wtc Pass true to avifDecoderDataGenerateImageGridTiles
2020-08-10 wtc Fail if any tile in an image grid is not supported
2020-08-10 wtc Add the disableGridImages setting to avifDecoder
2020-08-10 wtc Update codec_dav1d.c
2020-08-10 wtc Set max image size to 16384 * 16384
2020-08-10 wtc avifImageIdentity8ToRGB8ColorFullRange needs 4:4:4
2020-08-07 wtc Fix incorrect 8-to-16 monochrome YUV conversion
2020-08-06 jdrago Revert "Disable libgav1 until abseil-cpp stops using CMP0077 on newer CMake versions"
2020-08-05 wtc Check out Abseil release tag 20200225.2
2020-08-05 jdrago Update references of VS2017 in comments to VS2019 (minor)
2020-08-05 jdrago v0.8.1

Created with:
  roll-dep src/third_party/libavif/src

Disable grid images.

Test:
Manually test with
https://github.com/AOMediaCodec/av1-avif/blob/master/testFiles/Microsoft/Summer_in_Tomsk_720p_5x4_grid.avif

R=dalecurtis@chromium.org,pkasting@chromium.org

Bug: 1114916
Change-Id: I1c69c418e6ac82b91a0e89bb65bc06d6a9107a52
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2347085
Commit-Queue: Wan-Teh Chang <wtc@google.com>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#796913}

DEPS

@@ -342,7 +342,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling libavif
   # and whatever else without interference from each other.
-  'libavif_revision': '50c5bbd8f04ae9d8dc98556745b44476c3ce3223',
+  'libavif_revision': '4cfee6282b97533e6c99183ddf7a897173755c69',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling nearby
   # and whatever else without interference from each other.

third_party/blink/renderer/platform/image-decoders/avif/avif_image_decoder.cc

@@ -588,6 +588,10 @@ bool AVIFImageDecoder::MaybeCreateDemuxer() {
   if (!decoder_)
     return false;
 
+  // TODO(crbug.com/1114916): Disable grid image support in libavif until the
+  // libavif grid image code has been audited.
+  decoder_->disableGridImages = AVIF_TRUE;
+
   // TODO(dalecurtis): This may create a second copy of the media data in
   // memory, which is not great. libavif should provide a read() based API:
   // https://github.com/AOMediaCodec/libavif/issues/11