Fix nested border radius with composited child.

third_party/WebKit/LayoutTests/compositing/overflow/border-radius-on-two-ancestors-composited-grandchild.html

Index: third_party/WebKit/LayoutTests/compositing/overflow/border-radius-on-two-ancestors-composited-grandchild.html
diff --git a/third_party/WebKit/LayoutTests/compositing/overflow/border-radius-on-two-ancestors-composited-grandchild.html b/third_party/WebKit/LayoutTests/compositing/overflow/border-radius-on-two-ancestors-composited-grandchild.html
new file mode 100644
index 0000000000000000000000000000000000000000..e24c11e6bfa944f13608a93babf3645cb1f68b24
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/compositing/overflow/border-radius-on-two-ancestors-composited-grandchild.html
@@ -0,0 +1,40 @@
+<style>
+.outermost {
+	border: 4px solid #000;
+	width: 200px;
+	height: 200px;
+	border-radius: 40px;
+	overflow: hidden;
+}
+
+.middle {
+  border: 4px solid #888;
+  border-radius: 60px;
+  background-color: #008;
+  width: 200px;
+  height: 200px;
+  position: relative;
+  left: 100px;
+  top: 100px;
+  overflow: hidden;
+}
+
+.inner {
+  border: 4px solid #AAA;
+	width: 80px;
+	height: 400px;
+	background-color: #080;
+	position: relative;
+  left: 20px;
+  top: -100px;
+  will-change: transform;
+}
+</style>
+
+<div class="outermost">
+	<div class="middle">
+    <div class="inner">
+    </div>
+  </div>
+</div>
+