Use DOMSettableTokenList for {HTMLAnchorElement, HTMLAreaElement}.ping.

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

Index: third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp b/third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp
index 45c444fa841c36a4326989f5ae2a51b92fdb07a4..af9decff7091877f65348003fedad4d1b78dc33c 100644
--- a/third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp
@@ -52,6 +52,13 @@ HTMLAnchorElement::HTMLAnchorElement(const QualifiedName& tagName, Document& doc
 {
 }
 
+DEFINE_TRACE(HTMLAnchorElement)
+{
+    visitor->trace(m_ping);
+    HTMLElement::trace(visitor);
+    DOMSettableTokenListObserver::trace(visitor);
+}
+
 PassRefPtrWillBeRawPtr<HTMLAnchorElement> HTMLAnchorElement::create(Document& document)
 {
     return adoptRefWillBeNoop(new HTMLAnchorElement(aTag, document));
@@ -59,6 +66,10 @@ PassRefPtrWillBeRawPtr<HTMLAnchorElement> HTMLAnchorElement::create(Document& do
 
 HTMLAnchorElement::~HTMLAnchorElement()
 {
+#if !ENABLE(OILPAN)
+    if (m_ping)
+        m_ping->setObserver(nullptr);
+#endif
 }
 
 bool HTMLAnchorElement::supportsFocus() const
@@ -204,6 +215,8 @@ void HTMLAnchorElement::parseAttribute(const QualifiedName& name, const AtomicSt
         // Do nothing.
     } else if (name == relAttr) {
         setRel(value);
+    } else if (name == pingAttr) {
+        ping()->setValue(value);
     } else {
         HTMLElement::parseAttribute(name, oldValue, value);
     }
@@ -306,17 +319,24 @@ bool HTMLAnchorElement::isLiveLink() const
 
 void HTMLAnchorElement::sendPings(const KURL& destinationURL) const
 {
-    const AtomicString& pingValue = getAttribute(pingAttr);
-    if (pingValue.isNull() || !document().settings() || !document().settings()->hyperlinkAuditingEnabled())
+    if (!m_ping || m_ping->value().isNull() || !document().settings() || !document().settings()->hyperlinkAuditingEnabled())
         return;
 
     UseCounter::count(document(), UseCounter::HTMLAnchorElementPingAttribute);
 
-    SpaceSplitString pingURLs(pingValue, SpaceSplitString::ShouldNotFoldCase);
+    const SpaceSplitString& pingURLs = m_ping->tokens();
     for (unsigned i = 0; i < pingURLs.size(); i++)
         PingLoader::sendLinkAuditPing(document().frame(), document().completeURL(pingURLs[i]), destinationURL);
 }
 
+DOMSettableTokenList* HTMLAnchorElement::ping()
+{
+    if (!m_ping)
+        m_ping = DOMSettableTokenList::create(this);
+
+    return m_ping.get();
+}
+
 void HTMLAnchorElement::handleClick(Event* event)
 {
     event->setDefaultHandled();
@@ -363,6 +383,11 @@ void HTMLAnchorElement::handleClick(Event* event)
     }
 }
 
+void HTMLAnchorElement::valueWasSet()
+{
+    setSynchronizedLazyAttribute(pingAttr, m_ping->value());
+}
+
 bool isEnterKeyKeydownEvent(Event* event)
 {
     return event->type() == EventTypeNames::keydown && event->isKeyboardEvent() && toKeyboardEvent(event)->keyIdentifier() == "Enter";