Roll src/third_party/libavif/src/ 616bd4f9a..1d32f88ab (12 commits)

https://chromium.googlesource.com/external/github.com/AOMediaCodec/libavif.git/+log/616bd4f9aeca..1d32f88ab33e

$ git log 616bd4f9a..1d32f88ab --date=short --no-merges --format='%ad %ae %s'
2020-09-18 wtc Cleanup in avifPrepareReformatState()
2020-09-18 wtc Add four more aom-specific options
2020-09-16 wtc Document how to build dav1d with asan or ubsan
2020-09-16 wtc Move AOM-specific option processing to new func
2020-09-11 jdrago Disable receiving one-frame-per-layer when decoding scalable AVIFs with aom and dav1d
2020-09-11 jdrago Actually propagate the commandline codecChoice to the avifDecoder (!)
2020-09-11 jdrago Perform 0.5 UV bias with integers, as 128/512/2048 aren't exactly 0.5, but are expected to behave as such
2020-09-11 jdrago Add BT601 to drift calculations
2020-09-11 jdrago Avoid libpng's complaints about specific ICC profiles, and allow endusers to ignore an AVIF's ICC profile during conversion
2020-09-08 jdrago Store all alpha payloads before color payloads in mdat
2020-09-08 jdrago Fix memory leak in avifenc when encoding image sequences
2020-09-08 jdrago Error out with AVIF_RESULT_REFORMAT_FAILED if request uses an unsupported MC

Created with:
  roll-dep src/third_party/libavif/src
R=dalecurtis@chromium.org

Bug: 1130138
Change-Id: I0f362f84ae6173e6f864aa59aa12b05a4697fd0b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2422434Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Wan-Teh Chang <wtc@google.com>
Cr-Commit-Position: refs/heads/master@{#809132}

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': '616bd4f9aecaa38c1e1f83b4f79fd6df5d4b1467',
+  'libavif_revision': '1d32f88ab33e04b74f4e978bf30f0184d3a96011',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling nearby
   # and whatever else without interference from each other.