Use the pixelSnappedScrollWidth/Height for contentsSize

third_party/WebKit/LayoutTests/platform/mac-mac10.9/paint/invalidation/invalidate-caret-in-composited-scrolling-container-expected.txt

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true
     },
     {
       "name": "LayoutTextControl INPUT id='root'",
@@ skipping 21 matching lines @@
       "shouldFlattenTransform": false,
       "drawsContent": true
     },
     {
       "name": "Scrolling Layer",
       "bounds": [42, 13],
       "shouldFlattenTransform": false
     },
     {
       "name": "Scrolling Contents Layer",
-      "bounds": [67, 13],
+      "bounds": [68, 13],
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "LayoutText #text",
           "rect": [65, -1, 3, 15],
           "reason": "invalidate paint rectangle"
         }
       ]
     },
     {
@@ skipping 18 matching lines @@
       "object": "Caret",
       "reason": "invalidate paint rectangle"
     },
     {
       "object": "LayoutTextControl INPUT id='root'",
       "reason": "subtree"
     }
   ]
 }