Separate repaint and layout requirements of StyleDifference (Step 1)

LayoutTests/compositing/repaint/should-not-repaint-composited-styles-expected.txt

 position change with composited child
 
 position change with non-composited child
 
 z-index change with composited child
 
 z-index change with non-composited child
 
 opacity change with composited child
 
@@ skipping 31 matching lines @@
               )
             )
           )
         )
         (GraphicsLayer
           (position 8.00 260.00)
           (bounds 100.00 100.00)
           (drawsContent 1)
           (repaint rects
             (rect 0.00 0.00 100.00 100.00)
+            (rect 0.00 0.00 100.00 100.00)
           )
         )
         (GraphicsLayer
           (position 8.00 799.00)
           (bounds 100.00 100.00)
           (opacity 0.50)
           (children 1
             (GraphicsLayer
               (bounds 100.00 100.00)
               (children 1
@@ skipping 95 matching lines @@
           (drawsContent 1)
           (repaint rects
             (rect 0.00 0.00 100.00 100.00)
           )
         )
       )
     )
   )
 )