Update menu list text when popup is visible

http://src.chromium.org/viewvc/blink?view=rev&revision=184106
added updateFromElement() in RenderMenuList::popupDidHide()
to ensure the text is updated which wasn't updated when the
popup is visible.

This causes unnecessary invalidation when popup is closed when
selected item didn't change.

Now always update text in RenderMenuList::updateFromElement()
despite visibility of popup, and don't call updateFromElement()
from popupDidHide() to avoid unnecessary invalidation.

BTW fix an issue that the select title text was not updated
when selectedIndex is changed by program when the popup is
visible.

BUG=430857
TEST=fast/forms/select/menulist-update-text-popup.html

Review URL: https://codereview.chromium.org/706843004

git-svn-id: svn://svn.chromium.org/blink/trunk@184945 bbb929c8-8fbe-4397-9dbb-9b2b20218538