2023798 - [wpt-sync] Sync PR 58468 - [Fonts] Fix measureText() actualBoundingBox precision for MeasureRuns

Status: RESOLVED FIXED

(Core :: Graphics: Canvas2D, task, P4)

Description

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Sync web-platform-tests PR 58468 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/58468
Details from upstream follow.

Sejal Anand <[e-mail]> wrote:

[Fonts] Fix measureText() actualBoundingBox precision for MeasureRuns

The original fix (crrev.com/c/7564913) added PreciseBoundsForGlyph
for small font sizes but only applied it in GetActualBoundingBox(),
which handles the getActualBoundingBox(start, end) sub-range API.

The top-level measureText().actualBoundingBoxLeft/Right/Ascent/Descent
properties are computed via MeasureRuns() → InkBounds(), which still
used integer-precision BoundsForGlyph. This caused the original bug
to remain unfixed for the most commonly used API.

Apply PreciseBoundsForGlyph in MeasureRuns() for font sizes \<= 4px.

Also improve the WPT test:

• Move the WPT to the canvas test generator for coverage across
  HtmlCanvas, OffscreenCanvas, and Worker contexts.
• Switch from pixel-rendering check to direct metric assertions.
• Use glyph 'E' (has ascent + descent) and ±0.25 tolerances so
  integer-quantized values are reliably caught.

Bug: 479240778
Change-Id: I5e3f332b19ee0b7936a664bff5a87fa4cc780333
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7656848
Reviewed-by: Stephen Chenney \<[e-mail]>
Reviewed-by: Koji Ishii \<[e-mail]>
Commit-Queue: Sejal Anand \<[e-mail]>
Cr-Commit-Position: refs/heads/main@{#1599896}

Comment 1

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Pushed to try (stability) https://treeherder.mozilla.org/#/jobs?repo=try&revision=a28ec596c8e18c40466ce282a82859b3d89bffa6

Comment 2

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Attachment: Notable wpt changes

# CI Results

Ran 7 Firefox configurations based on mozilla-central, and Firefox, Chrome, and Safari on GitHub CI

Total 370 tests and 1 subtests

## Status Summary

### Firefox
`OK`  : 3[GitHub] 311[Gecko-windows11-64-24h2-debug] 312[Gecko-linux2404-64-debug, Gecko-linux2404-64-opt, Gecko-windows11-64-24h2-opt]
`PASS`: 26[Gecko-android-em-14-x86_64-lite-opt-geckoview, Gecko-android-em-14-x86_64-opt-geckoview] 35[Gecko-android-em-14-x86_64-debug-geckoview] 287[Gecko-linux2404-64-debug, Gecko-linux2404-64-opt] 289[Gecko-windows11-64-24h2-debug] 290[Gecko-windows11-64-24h2-opt]
`FAIL`: 3[GitHub] 15[Gecko-android-em-14-x86_64-debug-geckoview] 24[Gecko-android-em-14-x86_64-lite-opt-geckoview, Gecko-android-em-14-x86_64-opt-geckoview] 248[Gecko-windows11-64-24h2-debug, Gecko-windows11-64-24h2-opt] 251[Gecko-linux2404-64-debug, Gecko-linux2404-64-opt]

### Chrome
`OK`  : 3
`FAIL`: 3

### Safari
`OK`  : 3
`PASS`: 3

## Links
[Gecko CI (Treeherder)](https://treeherder.mozilla.org/#/jobs?repo=try&revision=a28ec596c8e18c40466ce282a82859b3d89bffa6)
[GitHub PR Head](https://wpt.fyi/results/?sha=36ddc485e32ef1a6a581f427fddbcd1240824394&label=pr_head)
[GitHub PR Base](https://wpt.fyi/results/?sha=36ddc485e32ef1a6a581f427fddbcd1240824394&label=pr_base)

## Details

(See attachment for full changes)

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/81ae798a9377
https://hg.mozilla.org/integration/autoland/rev/65d2d10a5b62
[wpt PR 58468] - [Fonts] Fix measureText() actualBoundingBox precision for MeasureRuns, a=testonly
https://github.com/mozilla-firefox/firefox/commit/dd11bafb7666
https://hg.mozilla.org/integration/autoland/rev/bfeda36d446f
[wpt PR 58468] - Update wpt metadata, a=testonly

Comment 4

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/65d2d10a5b62
https://hg.mozilla.org/mozilla-central/rev/bfeda36d446f