Make pseudo element update work with LocalStyleChange.

The missing pseudo element update on LocalStyleChange did not cause any bugs
at the moment since LocalStyleChange is not used when pseudo element selector
matching changes, but necessary to fix in preparation for optimizing :hover,
:active, and :focus updates using LocalStyleChange. If pseudo elements are
updated for LocalStyleChange, style updates for mentioned pseudo classes can
use LocalStyleChange in many cases where SubtreeStyleChange is currently used.

LocalStyleChange recalc style for the given element and descendants which
inherit any of the changes from that element. In addition, there is code
to make sure pseudo element children were being updated when the styles for
the element itself did not change, but matching of its pseudo elements did.

That code (shouldRecalcStyle() check on the actual element before calling
updatePseudoElement() in recalcChildStyle) was introduced in [1], but changed
behavior in [2] because needsRecalcStyle was cleared before recalcChildStyle.

UpdatePseudoElements is added as a new StyleRecalcChange which causes an
update of the pseudo element children, but not other children in the case
where the styles for the actual element were recalculated, but resulted in
NoChange or NoInherit, and any of the pseudo element bits were set on
RenderStyle.

[1] https://src.chromium.org/viewvc/blink?revision=147696&view=revision
[2] https://src.chromium.org/viewvc/blink?revision=161568&view=revision

BUG=337983

Review URL: https://codereview.chromium.org/144963002

git-svn-id: svn://svn.chromium.org/blink/trunk@165981 bbb929c8-8fbe-4397-9dbb-9b2b20218538