Fix RenderObject::repaintRectangle in situations when the render object is not a layer and is squashed.

Previously it was recording a repaint rect in the coordinate space of the enclosing *squashed* layer,
not the coordinate space of the *squashing layer* that the squashed layer paints into.
BUG=382129

Review URL: https://codereview.chromium.org/328533003

git-svn-id: svn://svn.chromium.org/blink/trunk@175843 bbb929c8-8fbe-4397-9dbb-9b2b20218538