Convert editing/selection/4932260-[123].html to utilize w3c test harness
This patch converts "4932260-[123].html" to utilize w3c test harness with
|assert_selection()| to simplify test case and consolidate into
"move_around_image.html" since these test files were committed in same patch for
improving code health.
This patch is a preparation of
http://crrev.com/1958093002
BUG=
625533
TEST=n/a; no behavior chagnes
Committed:
https://crrev.com/4426277e20a694987c4a324b385d07e79279ff2c
Cr-Commit-Position: refs/heads/master@{#428290}