Add a layout test for the RenderTableCell code in r145305.

That patch came with tests, but if you delete the added RenderTableCell code,
they still pass. I reconstructed this from the original page that broke
when this regression first happened.

Review URL: https://chromiumcodereview.appspot.com/21579005

git-svn-id: svn://svn.chromium.org/blink/trunk@155356 bbb929c8-8fbe-4397-9dbb-9b2b20218538