Use Ahem font in fast/images/color-profile-background-clip-text.html

We weren't pulling in the Ahem font correctly, leading to different
results on each platform (as a different fallback was chosen).

R=ccameron
BUG=624233

Review-Url: https://codereview.chromium.org/2368113003
Cr-Commit-Position: refs/heads/master@{#421699}
2 files changed