With the latest Editor's Draft of the CSS Shapes specification,
shape-outside no longer affects the positioning of floats. This is the
first step in changing the implementation to reflect this
specification change. The bulk of this change is reverting the code
that was needed to position floats based on the bounding box of the
shape.

This change removes the paintOffset methods and variables that were
originally added because the original positioning model for
shape-outside caused floats with shape-outside to behave like they were
positioned. Since that has been removed, the methods can be named as
they were originally: offsetForInFlowPosition, since they only handle
in flow positioned objects again.

This is a port of http://wkb.ug/118080

BUG=260357
R=ojan@chromium.org

Review URL: https://codereview.chromium.org/19295003

git-svn-id: svn://svn.chromium.org/blink/trunk@154321 bbb929c8-8fbe-4397-9dbb-9b2b20218538