Remove ENABLE_CUSTOM_ELEMENTS compile time flag

Source/core/dom/Document.idl

Index: Source/core/dom/Document.idl
diff --git a/Source/core/dom/Document.idl b/Source/core/dom/Document.idl
index cfadaff92306ebfeb4ea36a1e1b749937d70e667..d3b5d53a0e23e32ba0e6c2d5f16c9a060ed31a82 100644
--- a/Source/core/dom/Document.idl
+++ b/Source/core/dom/Document.idl
@@ -277,12 +277,10 @@
                                                      [Default=Undefined] optional float webkitForce);
     [ReturnNewObject, EnabledAtRuntime=touch, Custom, RaisesException] TouchList createTouchList();
 
-#if defined(ENABLE_CUSTOM_ELEMENTS) && ENABLE_CUSTOM_ELEMENTS
-    [EnabledAtRuntime=customDOMElements, Conditional=CUSTOM_ELEMENTS, ImplementedAs=registerElement, CallWith=ScriptState, DeliverCustomElementCallbacks, RaisesException] CustomElementConstructor webkitRegister(DOMString name, optional Dictionary options);
+    [EnabledAtRuntime=customDOMElements, ImplementedAs=registerElement, CallWith=ScriptState, DeliverCustomElementCallbacks, RaisesException] CustomElementConstructor webkitRegister(DOMString name, optional Dictionary options);
     [ReturnNewObject, DeliverCustomElementCallbacks, PerWorldBindings, ActivityLog=AccessForIsolatedWorlds, RaisesException] Element createElement(DOMString localName, [TreatNullAs=NullString] DOMString typeExtension);
     [ReturnNewObject, DeliverCustomElementCallbacks, PerWorldBindings, ActivityLog=AccessForIsolatedWorlds, RaisesException] Element createElementNS([TreatNullAs=NullString] DOMString namespaceURI, DOMString qualifiedName,
                             [TreatNullAs=NullString] DOMString typeExtension);
-#endif
 
     // Page visibility API.
     readonly attribute DOMString webkitVisibilityState;