[bindings] Make all CustomEvent.initCustomEvent arguments non-optional and remove custom binding.

Source/core/events/CustomEvent.h

Index: Source/core/events/CustomEvent.h
diff --git a/Source/core/events/CustomEvent.h b/Source/core/events/CustomEvent.h
index 5fa94c952c946bfc35f10707090e475fa4782103..82d5f357081a276ef90f0fac1c6cb51382693d19 100644
--- a/Source/core/events/CustomEvent.h
+++ b/Source/core/events/CustomEvent.h
@@ -49,6 +49,7 @@ public:
         return adoptRefWillBeNoop(new CustomEvent(type, initializer));
     }
 
+    void initCustomEvent(const AtomicString& type, bool canBubble, bool cancelable, const ScriptValue& detail);
     void initCustomEvent(const AtomicString& type, bool canBubble, bool cancelable, PassRefPtr<SerializedScriptValue>);
 
     const AtomicString& interfaceName() const override;
@@ -56,7 +57,6 @@ public:
     SerializedScriptValue* serializedDetail() { return m_serializedDetail.get(); }
 
     ScriptValue detail() const { return m_detail; }
-    void setDetail(ScriptValue detail) { m_detail = detail; }
 
     DECLARE_VIRTUAL_TRACE();