Enable slimming paint for fast/repaint

LayoutTests/fast/repaint/padding-keeping-content-size-expected.txt

Index: LayoutTests/fast/repaint/padding-keeping-content-size-expected.txt
diff --git a/LayoutTests/fast/repaint/padding-keeping-content-size-expected.txt b/LayoutTests/fast/repaint/padding-keeping-content-size-expected.txt
index e135b81117c09502a01fd70253c337f40c2faf0c..98b5e807cd9181d9a1c170e7b3ac0c3b79a82fa8 100644
--- a/LayoutTests/fast/repaint/padding-keeping-content-size-expected.txt
+++ b/LayoutTests/fast/repaint/padding-keeping-content-size-expected.txt
@@ -6,12 +6,17 @@
       "contentsOpaque": true,
       "drawsContent": true,
       "repaintRects": [
-        [100, 200, 40, 140],
         [100, 0, 40, 140],
         [20, 220, 100, 100],
-        [0, 300, 140, 40],
+        [0, 200, 140, 140],
+        [0, 200, 100, 100],
         [0, 200, 100, 100],
         [0, 100, 140, 40]
+      ],
+      "paintInvalidationClients": [
+        "LayoutBlockFlow (positioned) DIV id='target1' class='outer'",
+        "LayoutBlockFlow (positioned) DIV id='target2' class='outer'",
+        "LayoutBlockFlow DIV class='inner'"
       ]
     }
   ]