Autocomplete confused about direction if inline style and inherited dir attribute are mixed.

Both text box and autocomplete should have same direction i.e when the input box has a direction LTR, then autocomplete popup should also have the same direction
and vice-versa.

The present logic goes for finding dir attribute on the element and its parent which is the reason for autocomplete's incorrect direction when inline style and
inherited dir attribute are mixed. Now, we use renderStyle associated with a particular element to find out the direction (this takes into account both the
effect of dir attribute as well as the inline style).

BUG=397831
TBR=tkent@chromium.org

Review URL: https://codereview.chromium.org/419023007

git-svn-id: svn://svn.chromium.org/blink/trunk@179716 bbb929c8-8fbe-4397-9dbb-9b2b20218538