Inapplicable top, bottom style shouldn't affect height calculation

Require an absolute or fixed positioned containing block before
examining the containing block top and bottom style values for
contributing a non-auto height. Otherwise we'll base the decision on
inapplicable values.

|top| and |left| only applies to positioned elements:

http://www.w3.org/TR/CSS2/visuren.html#propdef-top
http://www.w3.org/TR/CSS2/visuren.html#propdef-bottom

and only contribute to the element's height (when height is auto) for
absolute and fixed positioned elements:

http://www.w3.org/TR/CSS2/visudet.html#normal-block
http://www.w3.org/TR/CSS2/visudet.html#abs-non-replaced-height

BUG=390101

Review URL: https://codereview.chromium.org/359673003

git-svn-id: svn://svn.chromium.org/blink/trunk@177374 bbb929c8-8fbe-4397-9dbb-9b2b20218538