Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/html/HTMLInputElement.cpp

Index: Source/core/html/HTMLInputElement.cpp
diff --git a/Source/core/html/HTMLInputElement.cpp b/Source/core/html/HTMLInputElement.cpp
index 7952c58f83be743b8803e9610ed433ab59f45558..03bb788a82123d35f12d842f94d1dfe6c684e543 100644
--- a/Source/core/html/HTMLInputElement.cpp
+++ b/Source/core/html/HTMLInputElement.cpp
@@ -157,6 +157,7 @@ void HTMLInputElement::willAddFirstAuthorShadowRoot()
 
 HTMLInputElement::~HTMLInputElement()
 {
+#if !ENABLE(OILPAN)
     // Need to remove form association while this is still an HTMLInputElement
     // so that virtual functions are called correctly.
     setForm(0);
@@ -166,6 +167,7 @@ HTMLInputElement::~HTMLInputElement()
         document().formController().radioButtonGroupScope().removeButton(this);

[haraken, 2014/04/25 05:21:42]

Would you elaborate on why it's safe to remove this line?

[Mads Ager (chromium), 2014/04/25 10:58:25]

Yes. With Oilpan, either the input element has been explicitly removed from the
document or the document is dead. If the element was explicitly removed,
removedFrom has called removeFromRadioButtonGroup which has already carried out
this work. If the document is dead, the formController (which is owned by the
Document) is dead and we don't need to remove this button from the set since it
will not be used.

     if (m_hasTouchEventHandler)
         document().didRemoveTouchEventHandler(this);
+#endif
 }
 
 const AtomicString& HTMLInputElement::name() const