Incrementally invalidate boxes with borders if possible

This actually restores RenderBox::incrementallyInvalidatePaint()
which was removed in http://src.chromium.org/viewvc/blink?view=revision&revision=177971
because it was buggy.

This change handles borders and border-radius.

BUG=390587

Review URL: https://codereview.chromium.org/399173005

git-svn-id: svn://svn.chromium.org/blink/trunk@180596 bbb929c8-8fbe-4397-9dbb-9b2b20218538