Don't force full repaint on size change in style

Move size change case from RenderStyle::diffNeedsFullLayoutAndRepaint()
into RenderStyle::diffNeedsFullLayout().

Also changed RenderObject::repaintAfterLayoutIfNeeded() to erase
the old rignt and/or bottom borders when needed during incremental
invalidation.

About tests:
- Existing test to be rebaselined: boxes not needing full repaint on
  resize is now go through incremental invalidation path;
- Though rebaselined, existing test with incorrect repaint expectations
  caused by crbug.com/380472 are still incorrect;
- One new test: fast/repaint/resize-with-border.html.

BUG=310875
TEST=See "About tests" above
R=esprehn@chromium.org

Review URL: https://codereview.chromium.org/312193004

git-svn-id: svn://svn.chromium.org/blink/trunk@176700 bbb929c8-8fbe-4397-9dbb-9b2b20218538