Move reattachWhitespaceSiblings() into recalcStyle instead of recalcChildStyle

Instead of returning a boolean and then checking it inside the loop we can
just move the call into Element::recalcStyle and Text::recalcTextStyle. This
makes the loop simpler and deletes a bunch of code.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/64633006

git-svn-id: svn://svn.chromium.org/blink/trunk@161760 bbb929c8-8fbe-4397-9dbb-9b2b20218538