Enable slimming paint for fast/repaint

LayoutTests/fast/repaint/window-resize-background-image-generated-expected.txt

Index: LayoutTests/fast/repaint/window-resize-background-image-generated-expected.txt
diff --git a/LayoutTests/fast/repaint/window-resize-background-image-generated-expected.txt b/LayoutTests/fast/repaint/window-resize-background-image-generated-expected.txt
index cedf98199985b44c1826ca5e57ea105dd240ec54..a64399685d29baaacbada73a6c79a0d7f34b1bde 100644
--- a/LayoutTests/fast/repaint/window-resize-background-image-generated-expected.txt
+++ b/LayoutTests/fast/repaint/window-resize-background-image-generated-expected.txt
@@ -6,8 +6,15 @@
       "contentsOpaque": true,
       "drawsContent": true,
       "repaintRects": [
+        [0, 200, 200, 100],
         [0, 0, 200, 300],
-        [0, 0, 200, 300]
+        [0, 0, 200, 8]
+      ],
+      "paintInvalidationClients": [
+        "VerticalScrollbar",
+        "LayoutView #document",
+        "LayoutView #document",
+        "LayoutBlockFlow HTML"
       ]
     }
   ]
@@ -20,8 +27,17 @@
       "contentsOpaque": true,
       "drawsContent": true,
       "repaintRects": [
+        [200, 0, 100, 300],
         [0, 0, 300, 300],
-        [0, 0, 300, 300]
+        [0, 0, 300, 8],
+        [0, 0, 200, 8]
+      ],
+      "paintInvalidationClients": [
+        "HorizontalScrollbar",
+        "LayoutView #document",
+        "LayoutView #document",
+        "LayoutBlockFlow HTML",
+        "LayoutBlockFlow BODY"
       ]
     }
   ]
@@ -34,8 +50,14 @@
       "contentsOpaque": true,
       "drawsContent": true,
       "repaintRects": [
+        [0, 250, 300, 50],
         [0, 0, 300, 250],
-        [0, 0, 300, 250]
+        [0, 0, 300, 8]
+      ],
+      "paintInvalidationClients": [
+        "LayoutView #document",
+        "LayoutView #document",
+        "LayoutBlockFlow HTML"
       ]
     }
   ]
@@ -48,8 +70,16 @@
       "contentsOpaque": true,
       "drawsContent": true,
       "repaintRects": [
+        [250, 0, 50, 250],
+        [0, 0, 300, 8],
         [0, 0, 250, 250],
-        [0, 0, 250, 250]
+        [0, 0, 250, 8]
+      ],
+      "paintInvalidationClients": [
+        "LayoutView #document",
+        "LayoutView #document",
+        "LayoutBlockFlow HTML",
+        "LayoutBlockFlow BODY"
       ]
     }
   ]