[PE] Improve SVG text selection for vertical text

We were previously always using the "left edge" of the fragment bounding
box when computing the position within the fragment. This works poorly
for vertical text. Use "top edge" for the vertical case instead.

Bug: 829214
Change-Id: I52e0aeffa95d05b1c86cd6aeca5dde7a886db486
Reviewed-on: https://chromium-review.googlesource.com/997792
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548722}
2 files changed