Fix fast/text/transform-text-first-line.html not to rely on a known issue

The new approach to apply the 'text-transform' property to
::first-line pseudo element[1] has a known issue that, since
it transforms at paint time, line breaking is measured
against non-transformed text.

The test fast/text/transform-text-first-line.html relies on
line breaking is measured against small letters, but this
issue does not exist in LayoutNG.

This patch fixes the test by using Ahem. Because Ahem has
different glyph but the same width for small letter 'p',
it can test which letters are capitalized without line
breaking being affected by the issue.

[1] https://chromium-review.googlesource.com/603855

TBR=eae@chromium.org

Bug: 129669, 644733, 636993
Change-Id: Ie0a14652c43d4b863ea0fd9bf40d8ab17f39d0ea
Reviewed-on: https://chromium-review.googlesource.com/1051067
Reviewed-by: Koji Ishii <kojii@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557129}
2 files changed