SelectorChecker::parentElement should walk up to ShadowHost only if an element is in a shadow tree …

LayoutTests/fast/dom/shadow/style-with-hat.html

Index: LayoutTests/fast/dom/shadow/style-with-hat.html
diff --git a/LayoutTests/fast/dom/shadow/style-with-hat.html b/LayoutTests/fast/dom/shadow/style-with-hat.html
index 929dd5c1a8c5d8551c94a355c90089c62e55a146..ee5ce12c0bf54d774b172c6f60d5d77da7815da9 100644
--- a/LayoutTests/fast/dom/shadow/style-with-hat.html
+++ b/LayoutTests/fast/dom/shadow/style-with-hat.html
@@ -324,6 +324,25 @@ borderColorShouldBe('host//host2/target', 'rgb(0, 128, 0)');
 
 cleanUp();
 
+sandbox.appendChild(
+    createDOM('div', {'id': 'host'},
+        createShadowRoot(
+            createDOM('style', {},
+                document.createTextNode('.x-bar .x-zot::shadow div { border: 1px solid red; }')),
+            createDOM('div', {'id': 'x-foo'},
+                document.createTextNode('x-foo')),
+            createDOM('div', {'id': 'x-bar-host', 'class': 'x-bar'},
+                createShadowRoot(
+                    createDOM('div', {'id': 'x-bar-target'},
+                        document.createTextNode('x-bar')),
+                    createDOM('div', {'id': 'x-zot-host', 'class': 'x-zot'},
+                        createShadowRoot(
+                            createDOM('div', {'id': 'x-zot-target'},
+                                document.createTextNode('x-zot')))))))));
+
+borderColorShouldNotBe('host/x-bar-host/x-zot-host/x-zot-target', 'rgb(255, 0, 0)');
+cleanUp();
+
 </script>
 </html>