Enable slimming paint for fast/repaint

LayoutTests/fast/repaint/selection-gap-fixed-child-expected.txt

Index: LayoutTests/fast/repaint/selection-gap-fixed-child-expected.txt
diff --git a/LayoutTests/fast/repaint/selection-gap-fixed-child-expected.txt b/LayoutTests/fast/repaint/selection-gap-fixed-child-expected.txt
index 7d362bdeed4d3a3baa1807b7daef85242ca6fd04..d3630c8d66cf068e52d38f923ac979f48b8bcd31 100644
--- a/LayoutTests/fast/repaint/selection-gap-fixed-child-expected.txt
+++ b/LayoutTests/fast/repaint/selection-gap-fixed-child-expected.txt
@@ -7,6 +7,16 @@
       "drawsContent": true,
       "repaintRects": [
         [0, 0, 100, 100]
+      ],
+      "paintInvalidationClients": [
+        "LayoutBlockFlow HTML",
+        "LayoutBlockFlow BODY",
+        "LayoutBlockFlow DIV",
+        "LayoutBR BR",
+        "InlineTextBox '\n'",
+        "LayoutBlockFlow (positioned) DIV id='target'",
+        "LayoutBR BR",
+        "InlineTextBox '\n'"
       ]
     }
   ]