[oilpan] The Node hierarchy should have correct accept method chains

Source/core/html/HTMLTextAreaElement.cpp

Index: Source/core/html/HTMLTextAreaElement.cpp
diff --git a/Source/core/html/HTMLTextAreaElement.cpp b/Source/core/html/HTMLTextAreaElement.cpp
index 06f755ea766cd311f89ec136ec74af046a6ef6eb..f053929ce39ff032cb516695b6a958a8b188d8f2 100644
--- a/Source/core/html/HTMLTextAreaElement.cpp
+++ b/Source/core/html/HTMLTextAreaElement.cpp
@@ -522,13 +522,13 @@ bool HTMLTextAreaElement::shouldUseInputMethod()
 
 HTMLElement* HTMLTextAreaElement::placeholderElement() const
 {
-    return m_placeholder;
+    return Handle<HTMLElement>(m_placeholder).raw();
 }
 
 void HTMLTextAreaElement::attach()
 {
     HTMLTextFormControlElement::attach();
-    fixPlaceholderRenderer(m_placeholder, innerTextElement());
+    fixPlaceholderRenderer(Handle<HTMLElement>(m_placeholder).raw(), innerTextElement());
 }
 
 bool HTMLTextAreaElement::matchesReadOnlyPseudoClass() const
@@ -546,23 +546,24 @@ void HTMLTextAreaElement::updatePlaceholderText()
     String placeholderText = strippedPlaceholder();
     if (placeholderText.isEmpty()) {
         if (m_placeholder) {
-            userAgentShadowRoot()->removeChild(m_placeholder, ASSERT_NO_EXCEPTION);
-            m_placeholder = 0;
+            userAgentShadowRoot()->removeChild(Handle<HTMLElement>(m_placeholder).raw(), ASSERT_NO_EXCEPTION);
+            m_placeholder = nullptr;
         }
         return;
     }
     if (!m_placeholder) {
         Handle<HTMLDivElement> placeholder = HTMLDivElement::create(document());
-        m_placeholder = placeholder.raw();
+        m_placeholder = placeholder;
         m_placeholder->setPseudo(AtomicString("-webkit-input-placeholder", AtomicString::ConstructFromLiteral));
-        userAgentShadowRoot()->insertBefore(m_placeholder, innerTextElement()->nextSibling(), ASSERT_NO_EXCEPTION);
+        userAgentShadowRoot()->insertBefore(Handle<HTMLElement>(m_placeholder).raw(), innerTextElement()->nextSibling(), ASSERT_NO_EXCEPTION);
     }
     m_placeholder->setInnerText(placeholderText, ASSERT_NO_EXCEPTION);
-    fixPlaceholderRenderer(m_placeholder, innerTextElement());
+    fixPlaceholderRenderer(Handle<HTMLElement>(m_placeholder).raw(), innerTextElement());
 }
 
 void HTMLTextAreaElement::acceptHeapVisitor(Visitor* visitor) const
 {
+    visitor->visit(m_placeholder);
     HTMLTextFormControlElement::acceptHeapVisitor(visitor);
 }