[text-box-trim] Support vertical flow
In doing this, this patch adds the FontBaseline variations
of Alphabetic(), CapHeight(), and XHeight() in the
FontMetrics class.
Also, the rounding methods in AdjustEdges() were different
from what FontMetrics::FixedAscent() does. This patch adds
Fixed variants to FontMetrics to make reviewing the
consistency easier.
All changes are under a currently disabled runtime flag.
Bug: 40254880
Change-Id: I470f1df976ff210ee7c3cdb336b73f44a59909d8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5539097
Reviewed-by: Kent Tamura tkent@chromium.org
Auto-Submit: Koji Ishii kojii@chromium.org
Commit-Queue: Koji Ishii kojii@chromium.org
Cr-Commit-Position: refs/heads/main@{#1301750}