Correct the squashing origin w.r.t. the transformed ancestor to take into account rounding to integ…

LayoutTests/compositing/squashing/squash-transform-repainting-transformed-child-expected.txt

Index: LayoutTests/compositing/squashing/squash-transform-repainting-transformed-child-expected.txt
diff --git a/LayoutTests/compositing/squashing/squash-transform-repainting-transformed-child-expected.txt b/LayoutTests/compositing/squashing/squash-transform-repainting-transformed-child-expected.txt
index 60737343805ce6daa369b5d9bf2a201496249e7f..c7eb9d5e64be9c078dba933991578e2b31bc96eb 100644
--- a/LayoutTests/compositing/squashing/squash-transform-repainting-transformed-child-expected.txt
+++ b/LayoutTests/compositing/squashing/squash-transform-repainting-transformed-child-expected.txt
@@ -50,8 +50,8 @@ CASE 2, hovering over the outer div
               (bounds 276.00 276.00)
               (drawsContent 1)
               (repaint rects
-                (rect 0.00 0.00 131.00 131.00)
-                (rect 0.00 0.00 131.00 131.00)
+                (rect 0.00 0.00 132.00 132.00)
+                (rect 0.00 0.00 132.00 132.00)
               )
             )
           )
@@ -83,10 +83,10 @@ CASE 3, hovering over the inner div
               (bounds 276.00 276.00)
               (drawsContent 1)
               (repaint rects
-                (rect 17.00 20.00 87.00 87.00)
-                (rect 17.00 20.00 87.00 87.00)
-                (rect 0.00 0.00 131.00 131.00)
-                (rect 0.00 0.00 131.00 131.00)
+                (rect 18.00 21.00 87.00 87.00)
+                (rect 18.00 21.00 87.00 87.00)
+                (rect 0.00 0.00 132.00 132.00)
+                (rect 0.00 0.00 132.00 132.00)
               )
             )
           )