Remove PaintLayerPaintingChildClippingMaskPhase.

sky/tests/clipping/canvas-rounded-corners-expected.txt

Index: sky/tests/clipping/canvas-rounded-corners-expected.txt
diff --git a/sky/tests/clipping/canvas-rounded-corners-expected.txt b/sky/tests/clipping/canvas-rounded-corners-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..26195d243b7512b6ec85840ba983d8176920325e
--- /dev/null
+++ b/sky/tests/clipping/canvas-rounded-corners-expected.txt
@@ -0,0 +1,24 @@
+layer at (0,0) size 800x600
+  RenderView {#document} at (0,0) size 800x600
+layer at (0,0) size 800x353
+  RenderBlock {sky} at (0,0) size 800x353
+    RenderBlock {h3} at (0,0) size 800x19
+      RenderBlock (anonymous) at (0,0) size 800x19
+        RenderText {#text} at (0,0) size 92x19
+          text run at (0,0) width 92: "It passes if:"
+    RenderBlock {ul} at (0,19) size 800x57
+      RenderBlock {li} at (0,0) size 800x19
+        RenderBlock (anonymous) at (0,0) size 800x19
+          RenderText {#text} at (0,0) size 511x19
+            text run at (0,0) width 511: "the canvas content has rounded corners (top-left and top-right)"
+      RenderBlock {li} at (0,19) size 800x19
+        RenderBlock (anonymous) at (0,0) size 800x19
+          RenderText {#text} at (0,0) size 457x19
+            text run at (0,0) width 457: "the 10px red border is visible around the canvas content"
+      RenderBlock {li} at (0,38) size 800x19
+        RenderBlock (anonymous) at (0,0) size 800x19
+          RenderText {#text} at (0,0) size 200x19
+            text run at (0,0) width 200: "gray border is not visible"
+layer at (0,76) size 277x277
+  RenderHTMLCanvas {canvas} at (0,76) size 277x277 [bgcolor=#808080] [border: (10px solid #FF0000)]
+