GitLab

Before laying out, we try to estimate and set the logical top of the child, but
it may turn out after one layout pass that the estimate was wrong, due to
margin collapsing, float clearance or pagination.

So sometimes we need to reposition and relayout once or even twice inside
layoutBlockChild(). This was done with slightly poorly duplicated code.
Refactor into positionAndLayoutOnceIfNeeded() (and
markDescendantsWithFloatsForLayoutIfNeeded()). One instance of this duplicated
code used to sit in adjustBlockChildForPagination(). Moved it into
layoutBlockChild(), to make it easier to understand what's going on (and to
give adjustBlockChildForPagination() one less thing to worry about - one
parameter removed). Renamed |result| to |newLogicalTop| in
adjustBlockChildForPagination(), and |logicalTopAfterClear| to |newLogicalTop|
in layoutBlockChild().

No behavioral changes were actually intended, but when unifying
almost-duplicated code, some changes are inevitable. Added some tests for
something that now works, and used to fail. In the subsequent layout passes we
forgot to check if the new position changed how we were affected by floats.

R=jchaffraix@chromium.org,leviw@chromium.org

Review URL: https://codereview.chromium.org/1315353005

git-svn-id: svn://svn.chromium.org/blink/trunk@201866 bbb929c8-8fbe-4397-9dbb-9b2b20218538