Convert editing/insert-text-with-newlines.html to use w3c test harness
This patch converts "editing/insert-text-with-newlines.html" to use w3c test
harness to simplify 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/59f000d102e7f801cfb580ed0bdf58e13eb0d3c7
Cr-Commit-Position: refs/heads/master@{#407694}