Remove the support of multiple shadow roots with a user agent shadow root

third_party/WebKit/LayoutTests/fast/dom/shadow/olderShadowRoot.html

Index: third_party/WebKit/LayoutTests/fast/dom/shadow/olderShadowRoot.html
diff --git a/third_party/WebKit/LayoutTests/fast/dom/shadow/olderShadowRoot.html b/third_party/WebKit/LayoutTests/fast/dom/shadow/olderShadowRoot.html
index 4517e7f6b007a88ef9176d75b2742cbf6a3d5321..4e7dbfab1c609096dab77d1389dd645c01d2be1a 100644
--- a/third_party/WebKit/LayoutTests/fast/dom/shadow/olderShadowRoot.html
+++ b/third_party/WebKit/LayoutTests/fast/dom/shadow/olderShadowRoot.html
@@ -42,20 +42,7 @@ host = document.createElement('table');
 root = host.createShadowRoot();
 shouldBeNull('root.olderShadowRoot');
 
-// Cannot access a user-agent shadow	
-
-host = document.createElement('details');	
-root = host.createShadowRoot();	
-shouldBeNull('root.olderShadowRoot');	
-
-host = document.createElement('summary');	
-document.body.appendChild(host);	
-root = host.createShadowRoot();	
-shouldBeNull('root.olderShadowRoot');	
-host.remove();
-
 // Cannot set property
-
 host = document.createElement('span');
 roots = createRoots(host, 2);
 var donor = document.createElement('div');
@@ -63,15 +50,6 @@ donor.root = donor.createShadowRoot();
 roots[1].olderShadowRoot = donor.root;
 shouldBe('roots[1].olderShadowRoot', 'roots[0]');
 
-host = document.createElement('details');	
-document.body.appendChild(host);	
-root = host.createShadowRoot();	
-donor = document.createElement('div');	
-donor.root = donor.createShadowRoot();	
-root.olderShadowRoot = donor.root;	
-shouldBeNull('root.olderShadowRoot');	
-host.remove();
-
 successfullyParsed = true;
 </script>
 </body>