Properly repaint RenderLayer's descendants when it moves

When a RenderLayer moves, it can cause non-composited descendants of itself
that are placed relatively to it to need to be repainted. These descandants
may not have needed layout themselves, nor have they moved as far as the
RenderLayer itself is concerned. This patch forces all descendant RenderLayers
of a moved ancestor to at a minimum be checked by invalidateTreeAfterLayout
to see if they need to be repainted.

Ideally we'd bail in markDescendantLayersMayNeedPaintInvalidation when
we hit a composited layer, but because updateLayerPositions occurs before
compositing update, this would be a chicken and egg problem.

BUG=385103

Review URL: https://codereview.chromium.org/354613003

git-svn-id: svn://svn.chromium.org/blink/trunk@176880 bbb929c8-8fbe-4397-9dbb-9b2b20218538