Convert editing/execCommand/insertHorizontalRule.html to use w3c test harness
This patch converts "editing/execCommand/insertHorizontalRule.html" to use w3c
test harness to simplify test files.
This patch also renames it to "insert_horizontal_rule.html" to follow other
test files.
This patch is a preparation of getting rid of grammar checking feature.
BUG=
619452
TEST=n/a; this patch changes a test file
Committed:
https://crrev.com/40247bdd0ab99581e5d1aff147a0e01694a106f7
Cr-Commit-Position: refs/heads/master@{#407404}