[SPInvalidation] Handle pixel-snapping of paint invalidation rects

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=SlimmingPaintInvalidation/paint/invalidation/flexbox/repaint-rtl-column-expected.txt

 {
   "layers": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "paintInvalidations": [
         {
           "object": "LayoutBlockFlow DIV id='content'",
           "rect": [8, 116, 200, 252],
           "reason": "style change"
         },
         {
           "object": "LayoutBlockFlow DIV id='content'",
           "rect": [8, 119, 200, 249],
           "reason": "style change"
         },
         {
           "object": "LayoutBlockFlow DIV id='left'",
-          "rect": [8, 119, 200, 94],
-          "reason": "incremental"
+          "rect": [8, 68, 200, 145],
+          "reason": "bounds change"
         },
         {
           "object": "LayoutBlockFlow DIV id='left'",
-          "rect": [8, 116, 200, 4],
-          "reason": "incremental"
+          "rect": [8, 68, 200, 52],
+          "reason": "bounds change"
         },
         {
           "object": "LayoutBlockFlow DIV",
           "rect": [13, 124, 190, 351],
           "reason": "bounds change"
         },
         {
           "object": "LayoutBlockFlow DIV",
           "rect": [13, 124, 190, 351],
           "reason": "bounds change"
         },
         {
           "object": "LayoutBlockFlow DIV",
           "rect": [13, 121, 190, 351],
           "reason": "bounds change"
         },
         {
           "object": "LayoutBlockFlow DIV",
           "rect": [13, 218, 190, 350],
           "reason": "bounds change"
         }
       ]
     }
   ],
   "objectPaintInvalidations": [
     {
       "object": "LayoutBlockFlow DIV id='left'",
-      "reason": "incremental"
+      "reason": "bounds change"
     },
     {
       "object": "LayoutBlockFlow DIV id='content'",
       "reason": "style change"
     },
     {
       "object": "LayoutBlockFlow DIV",
       "reason": "bounds change"
     },
     {
       "object": "LayoutBlockFlow DIV id='left'",
-      "reason": "incremental"
+      "reason": "bounds change"
     },
     {
       "object": "LayoutBlockFlow DIV id='content'",
       "reason": "style change"
     },
     {
       "object": "LayoutBlockFlow DIV",
       "reason": "bounds change"
     }
   ]
 }