Port pixelzoomer.js/css to ct-results-comparison.

Port pixelzoomer.js/css to ct-results-comparison.

This broke when I changed the results comparison to use polymer components.
This isn't 100% the same as the old pixelzoomer code. I took this as an
opportunity to simplify it.

Also, change the 4-space indent to 2-space indent and replace
endOfMicroTask calls with requestAnimationFrame to match the rest of
the codebase.

NOTRY=true

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=178536

[ojan, 2014-07-20 03:27:57]

This patch and leviw's revisions notification patch are the final bits to be
feature complete in the polymer port. I don't think we need to wait for either
to land though. We can start deleting the old code now!

This patch is ready other than the lack of tests. The old code was completely
untested. :( Just posting this in case someone else was going to work on this so
they don't waste their time.

[abarth-chromium, 2014-07-20 16:48:12]

Wow, so much cleaner.

This can't be a separate component that you add to ct-results-comparison?

[ojan, 2014-07-20 23:31:35]

This is ready for review now.

[abarth-chromium, 2014-07-21 06:12:50]

LGTM

[abarth-chromium, 2014-07-21 06:12:56]

The CQ bit was checked by abarth@chromium.org

[commit-bot: I haz the power, 2014-07-21 06:13:04]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/ojan@chromium.org/403983002/20001

[commit-bot: I haz the power, 2014-07-21 06:13:29]

Change committed as 178536