Option, checkbox and radio should support ':default' selector

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

Index: third_party/WebKit/Source/core/html/HTMLInputElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLInputElement.cpp b/third_party/WebKit/Source/core/html/HTMLInputElement.cpp
index 1a52b21e6db3ad6dc24f78a46ace39a749f65a1f..180b66d6e8fca59adb244c6cfafaa70148fe64f5 100644
--- a/third_party/WebKit/Source/core/html/HTMLInputElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLInputElement.cpp
@@ -1658,6 +1658,11 @@ bool HTMLInputElement::supportLabels() const
     return m_inputType->isInteractiveContent();
 }
 
+bool HTMLInputElement::isDefaultButtonForForm() const
+{
+    return m_inputType->matchesDefaultPseudoClass();
+}
+
 bool HTMLInputElement::shouldAppearChecked() const
 {
     return checked() && m_inputType->isCheckable();