Implement ShadowRoot.delegatesFocus 4/4 (match CSS :focus for shadow host)

Source/core/dom/ContainerNode.cpp

Index: Source/core/dom/ContainerNode.cpp
diff --git a/Source/core/dom/ContainerNode.cpp b/Source/core/dom/ContainerNode.cpp
index f399213a53970bcd7f8a6b467d8ce43cac065ba5..b709a75b3be82927d8aafce0084aea0184e5c589 100644
--- a/Source/core/dom/ContainerNode.cpp
+++ b/Source/core/dom/ContainerNode.cpp
@@ -1084,6 +1084,19 @@ void ContainerNode::focusStateChanged()
 
 void ContainerNode::setFocus(bool received)
 {
+    // Recurse up author shadow trees to mark shadow hosts if it matches :focus.
+    // TODO(kochi): Handle UA shadows which marks multiple nodes as focused such as
+    // <input type="date"> the same way as author shadow.
+    if (isInShadowTree() && shadowHost()->shadowRoot())

[hayato, 2015/06/12 07:59:29]

How about this? The intention would becomes more clear.

if (ShadowRoot* root = element.containingShadowRoot())
  if (root->type() == ShadowRoot::AuthorShadowRoot)

Or, you might want to add a new utility function.  e.g
Node::isInAuthorShadowTree().

[kochi, 2015/06/12 08:21:35]

Adopted your first suggestion.

+        shadowHost()->setFocus(received);
+
+    // If this is an author shadow host and indirectly focused (has focused element within
+    // its shadow root), update focus.
+    if (isElementNode() && document().focusedElement() && document().focusedElement() != this) {
+        if (toElement(this)->shadowRoot())
+            received = received && toElement(this)->shadowRoot()->delegatesFocus();
+    }
+
     if (focused() == received)
         return;