Implement HTMLElement directionality according to the spec

Implement HTMLElement directionality according to the spec

The current spec for directionality:
http://www.whatwg.org/specs/web-apps/current-work/multipage/dom.html#the-directionality says that:

- If the element is an input element whose type attribute is in the Text, Search, Telephone,
URL, or E-mail state, and the dir attribute is in the auto state
- If the element is a textarea element and the dir attribute is in the auto state
-- If the element's value contains a character of bidirectional character type AL or R, and there
   is no character of bidirectional character type L anywhere before it in the element's value,
   then the directionality of the element is 'rtl'. [BIDI]

-- Otherwise, if the element's value is not the empty string, or if the element is a root element,
   the directionality of the element is 'ltr'.

-- Otherwise, the directionality of the element is the same as the element's parent element's
   directionality.

[Sunil Ratnu, 2014-09-09 03:37:36]

sunil.ratnu@samsung.com changed reviewers:
+ tkent@chromium.org

[Sunil Ratnu, 2014-09-09 03:37:37]

Please review this. Thanks!

[rwlbuis, 2015-03-23 22:43:19]

On 2014/09/09 03:37:37, Sunil Ratnu wrote:
> Please review this. Thanks!

Hi Sunil, are you still working on this? This probably needs to be rebased
against latest trunk, I should be able to trigger buildbots if you can't. That
may show us if anything breaks, if not then maybe all that is left is add a
test.

[Sunil Ratnu, 2015-03-24 12:15:55]

On 2015/03/23 22:43:19, rwlbuis wrote:
> On 2014/09/09 03:37:37, Sunil Ratnu wrote:
> > Please review this. Thanks!
> 
> Hi Sunil, are you still working on this? This probably needs to be rebased
> against latest trunk, I should be able to trigger buildbots if you can't. That
> may show us if anything breaks, if not then maybe all that is left is add a
> test.

It was not failing any existing tests previously. I will rebase it and will add
a test case.