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This patch makes editing/selection/vertical-*.html to use w3c test harness
rather than pixel match for ease of maintain.

This is the first patch of three patches of rewriting vertical-*.html.
Due by Windows command prompt limitation, we can't upload once.

BUG=n/a
TEST=n/a; no behavior changes

Review URL: https://codereview.chromium.org/1466543003

Cr-Commit-Position: refs/heads/master@{#361270}