1876382 - [wpt-sync] Sync PR 44175 - wire up primary font load timings

Status: NEW

(Testing :: web-platform-tests, task, P4)

Description

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

Sync web-platform-tests PR 44175 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/44175
Details from upstream follow.

Hao Liu <[e-mail]> wrote:

wire up primary font load timings

This CL wires up the load timings of a web font into the text LCP
record as the LCP breakdown timings of that text element.
When a text node is painted, it is enqueued as an LCP candidate.
At this place We check if the applied fonts of the text node contains
the primary font of the fallback font list.
If it does, it means the primary font is applied. Then if the primary
font is a web font, we retrieve the load timings of the web font and
pass them to the text record.
The load timings of the web font is set to a newly added member field
of the CustomFontData object when the resource fetching finish is
notified to the ResourceClient RemoteFontFaceSource object.

Bug: 40276574
Change-Id: Ic13b9d882a97ce0b5101a3cf4693ca1ce2b5ceac
Reviewed-on: https://chromium-review.googlesource.com/5232893
WPT-Export-Revision: 1a9ad6f765ececf1289d546b5ec421be2d19f6e1