Add test for style 'transform' vs. presentation attribute 'transform'

The former should "win" over the latter.
Fixed by https://codereview.chromium.org/2478233002.

TBR=pdr@chromium.org
BUG=415950

Review-Url: https://codereview.chromium.org/2621153005
Cr-Commit-Position: refs/heads/master@{#442980}
2 files changed