Fix invalidation under scroll, and cull rect testing, of flipped-block writing mode elements.

third_party/WebKit/LayoutTests/paint/invalidation/flipped-blocks-writing-mode-scroll-expected.txt

 {
   "name": "Content Root Layer",
   "bounds": [800, 600],
   "children": [
     {
       "name": "LayoutView #document",
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "children": [
         {
-          "name": "LayoutBlockFlow (positioned) DIV id='scroller'",
-          "position": [300, 300],
-          "bounds": [200, 200],
+          "name": "LayoutBlockFlow DIV id='scroller'",
+          "position": [8, 8],
+          "bounds": [400, 400],
           "shouldFlattenTransform": false,
           "drawsContent": true,
           "children": [
             {
               "name": "Scrolling Layer",
-              "bounds": [185, 200],
+              "bounds": [400, 385],
               "shouldFlattenTransform": false,
               "children": [
                 {
                   "name": "Scrolling Contents Layer",
-                  "bounds": [185, 4900],
+                  "bounds": [10000, 385],
                   "drawsContent": true,
                   "paintInvalidations": [
                     {
                       "object": "LayoutBlockFlow DIV id='target'",
-                      "rect": [0, 2400, 100, 100],
+                      "rect": [0, 0, 10000, 200],
                       "reason": "style change"
                     }
                   ]
                 }
               ]
             },
             {
               "name": "Overflow Controls Host Layer",
-              "bounds": [200, 200],
+              "bounds": [400, 400],
               "children": [
                 {
-                  "name": "Vertical Scrollbar Layer",
-                  "position": [185, 0],
-                  "bounds": [15, 200],
+                  "name": "Horizontal Scrollbar Layer",
+                  "position": [0, 385],
+                  "bounds": [400, 15],
                   "paintInvalidations": [
                     {
-                      "object": "Vertical Scrollbar Layer",
-                      "rect": [0, 0, 15, 200],
+                      "object": "Horizontal Scrollbar Layer",
+                      "rect": [0, 0, 400, 15],
                       "reason": "full"
                     }
                   ]
                 }
               ]
             }
           ]
         }
       ]
     }
   ],
   "objectPaintInvalidations": [
     {
       "object": "LayoutBlockFlow DIV id='target'",
       "reason": "style change"
     }
   ]
 }