Have SkWuffsCodec speak kRGB_565_SkColorType

This takes the "one pass" code path more often, using less memory, as it
does not have to allocate an intermediate width*height pixel buffer.

Wuffs v0.2 did not support RGB 565 color but Wuffs v0.3 does.

The Codec_AnimatedTransparentGif test passes with skia_use_wuffs true or
false.

Change-Id: Id569fc0bf62e614fa881cb235a9a6a1ca340dcb0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/329916
Commit-Queue: Leon Scroggins <scroggo@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
2 files changed