Revert of id of iframe incorrectly sets window name (https://codereview.chromium.org/187103002/)

Reason for revert:
This have broken browser_tests according to my bisect:
http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests%20%28dbg%29/builds/2034/steps/browser_tests/logs/TabDestroyed

Original issue's description:
> id of iframe incorrectly sets window name
>
> As per the specification, the iframe's name should be an empty string if unset:
> http://www.whatwg.org/specs/web-apps/current-work/multipage/the-iframe-element.html#attr-iframe-name
>
> Instead, Chromium was using the iframe's id as window name if the name was
> unset. This change makes us behave like Firefox 27 and IE 11, verified using:
> http://jsfiddle.net/xf5H7/9/
>
> This CL sets the name attribute iframe in a lot of layout tests so that
> testRunner.dumpChildFramesAsText() keeps printing the same result.
>
> R=arv@chromium.org, tkent@chromium.org
> BUG=347169
> TEST=fast/frames/iframe-no-name.html
>
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=168553
>
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=168801
>
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169304
>
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169683

TBR=abarth@chromium.org,arv@chromium.org,tkent@chromium.org,ch.dumez@samsung.com
NOTREECHECKS=true
NOTRY=true
BUG=347169

Review URL: https://codereview.chromium.org/198183003

git-svn-id: svn://svn.chromium.org/blink/trunk@169726 bbb929c8-8fbe-4397-9dbb-9b2b20218538