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

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

Index: third_party/WebKit/Source/core/html/HTMLOptionElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLOptionElement.cpp b/third_party/WebKit/Source/core/html/HTMLOptionElement.cpp
index 4c8bf9095afa16b36369b4cb6504a7c19e1e1060..57b8794b491c8f214cd084412a2592c78690eea6 100644
--- a/third_party/WebKit/Source/core/html/HTMLOptionElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLOptionElement.cpp
@@ -115,6 +115,11 @@ bool HTMLOptionElement::supportsFocus() const
     return HTMLElement::supportsFocus();
 }
 
+bool HTMLOptionElement::isDefaultButtonForForm() const
+{
+    return fastHasAttribute(selectedAttr);
+}
+
 String HTMLOptionElement::displayLabel() const
 {
     Document& document = this->document();