Reland: [COLRv1] Support retrieving ClipBox.

Reland after MSAN failure, initializing SkRect to empty in
computeColrV1GlyphBoundingBox().

After the discussion in [1] which was filed also in response to feedback
from Ben, the COLRv1 spec moved to not using a bounding box derived from
the `glyf` glyph for a give glyph id, but instead either use a ClipBox
found for a particular glyph id range from a ClipList array in the
COLRv1 table. If such a ClipBox is not found, perform a traversal of the
COLRv1 graph to compute the union of rectangles to compute a bounding
box.

[1] https://github.com/googlefonts/colr-gradients-spec/issues/251

Includes FreeType roll:
https://chromium.googlesource.com/chromium/src/third_party/freetype2.git/+log/47b1a541cb1943d85da3976b93f9a5ed490288e2..2c853b38a717c615d3113a64033fc896e5888fa8

Fixed: skia:12297
Cq-Include-Trybots: luci.skia.skia.primary:Test-Android-Clang-GalaxyS6-GPU-MaliT760-arm64-Release-All-Android_NativeFonts, luci.skia.skia.primary:FM-Debian10-Clang-GCE-CPU-AVX2-x86_64-Release-All-MSAN
Change-Id: I165fb95c89045c4c7671af2cbe097af38ca65e84
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/437996
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
6 files changed