Move Node::retarget() to TreeScope::retarget()

third_party/WebKit/Source/core/dom/TreeScope.cpp

Index: third_party/WebKit/Source/core/dom/TreeScope.cpp
diff --git a/third_party/WebKit/Source/core/dom/TreeScope.cpp b/third_party/WebKit/Source/core/dom/TreeScope.cpp
index 3ef34953971daa4b38e5226a8930cae4be902b5f..6e7bb65a900cbfaeef7fdda3bd186384e7c9f2fc 100644
--- a/third_party/WebKit/Source/core/dom/TreeScope.cpp
+++ b/third_party/WebKit/Source/core/dom/TreeScope.cpp
@@ -420,6 +420,15 @@ void TreeScope::adoptIfNeeded(Node& node)
         adopter.execute();
 }
 
+Element* TreeScope::retarget(const Element& target) const
+{
+    for (const Element* ancestor = ⌖ ancestor; ancestor = ancestor->shadowHost()) {
+        if (this == ancestor->treeScope())
+            return const_cast<Element*>(ancestor);
+    }
+    return nullptr;
+}
+
 Element* TreeScope::adjustedFocusedElement() const
 {
     Document& document = rootNode().document();
@@ -430,9 +439,8 @@ Element* TreeScope::adjustedFocusedElement() const
         return nullptr;
 
     if (rootNode().isInV1ShadowTree()) {
-        if (Node* retargeted = rootNode().retarget(*element)) {
-            DCHECK(retargeted->isElementNode());
-            return this == &retargeted->treeScope() ? toElement(retargeted) : nullptr;
+        if (Element* retargeted = retarget(*element)) {
+            return (this == &retargeted->treeScope()) ? retargeted : nullptr;

[kochi, 2016/04/15 05:40:46]

Is there any chance that the result of retarget() is in a different tree scope?
If not the body for outer if is just "return retargeted(*element);".

[hayato, 2016/04/15 07:30:52]

Let me leave this as is.

I am aware that the current Node::retarget does not match the spec, though the
current behavior is enough for adjustedFocusedElement.

I will update the TreeScope::retarget() in another patch with a layout test, to
make it match the spec.

         }
         return nullptr;
     }