Fix RenderText multiline elision for RTL.

RTL text segments have their char_range reversed. Instead of just taking
the first segment of the line, iterate and find the smallest index. Note
that we can not simply check the first and last one, as text might have
mixed segments of RTL and LTR segments.

Bug: None
Change-Id: I03541836fcbc5a115ad7785f7a72ffc0ab95bec0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1619687
Reviewed-by: Michael Wasserman <msw@chromium.org>
Commit-Queue: Richard Knoll <knollr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663259}
6 files changed