Remove redundant calls to HTMLSelectElement::setRecalcListItems().

third_party/WebKit/Source/core/html/HTMLHRElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLHRElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLHRElement.cpp b/third_party/WebKit/Source/core/html/HTMLHRElement.cpp
index 4292a119ab57c0d896fe22073caf277f21b92073..6a67cc7c0e9ffd73d5d71299d3f51b4a96d9a547 100644
--- a/third_party/WebKit/Source/core/html/HTMLHRElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLHRElement.cpp
@@ -27,6 +27,8 @@
 #include "core/HTMLNames.h"
 #include "core/css/CSSColorValue.h"
 #include "core/css/StylePropertySet.h"
+#include "core/html/HTMLOptGroupElement.h"
+#include "core/html/HTMLSelectElement.h"
 
 namespace blink {
 
@@ -90,4 +92,39 @@ void HTMLHRElement::collectStyleForPresentationAttribute(const QualifiedName& na
     }
 }
 
+HTMLSelectElement* HTMLHRElement::ownerSelectElement() const
+{
+    if (!parentNode())
+        return nullptr;
+    if (isHTMLSelectElement(*parentNode()))
+        return toHTMLSelectElement(parentNode());
+    if (!isHTMLOptGroupElement(*parentNode()))
+        return nullptr;
+    Node* grandParent = parentNode()->parentNode();
+    return isHTMLSelectElement(grandParent) ? toHTMLSelectElement(grandParent) : nullptr;
+}
+
+Node::InsertionNotificationRequest HTMLHRElement::insertedInto(ContainerNode* insertionPoint)
+{
+    HTMLElement::insertedInto(insertionPoint);
+    if (HTMLSelectElement* select = ownerSelectElement()) {
+        if (insertionPoint == select || (isHTMLOptGroupElement(*insertionPoint) && insertionPoint->parentNode() == select))

[keishi, 2016/06/29 08:46:40]

Isn't existence of ownerSelectElement enough? do we need to check
insertionPoint?

[tkent, 2016/06/29 08:58:04]

Checking only existence of ownerSelectElement isn't efficient.  It would call
hrInsertedOrRemoved() even if a subtree including <select><hr/>...</select> is
appended to another element.

+            select->hrInsertedOrRemoved(*this);
+    }
+    return InsertionDone;
+}
+
+void HTMLHRElement::removedFrom(ContainerNode* insertionPoint)
+{
+    if (isHTMLSelectElement(*insertionPoint)) {
+        if (!parentNode() || isHTMLOptGroupElement(*parentNode()))
+            toHTMLSelectElement(insertionPoint)->hrInsertedOrRemoved(*this);
+    } else if (isHTMLOptGroupElement(*insertionPoint)) {
+        Node* parent = insertionPoint->parentNode();
+        if (isHTMLSelectElement(parent))
+            toHTMLSelectElement(parent)->hrInsertedOrRemoved(*this);
+    }
+    HTMLElement::removedFrom(insertionPoint);
+}
+
 } // namespace blink