Convert editing/inserting/insert-div-025.html to use w3c test harness
This patch converts "editing/inserting/insert-div-025.html" to use w3c test
harness to simplify test script for improving readability.
BUG=n/a
TEST=n/a; no behavior changes
Committed:
https://crrev.com/609868733e176ecad4bb6db66865cca9a326780f
Cr-Commit-Position: refs/heads/master@{#415238}