Rename Sky's custom2 to custom

sky/engine/build/scripts/templates/ElementFactory.cpp.tmpl

 {% from "macros.tmpl" import license %}
 {{ license() }}
 
 #include "config.h"
 #include "{{namespace}}ElementFactory.h"
 
 #include "{{namespace}}Names.h"
 {% for tag in tags|sort %}
 #include "core/{{namespace|lower}}/{{tag.interface}}.h"
 {% endfor %}
 {% if fallback_interface %}
 #include "core/{{namespace|lower}}/{{fallback_interface}}.h"
 {% endif %}
-#include "core/dom/custom2/new_custom_element_registry.h"
+#include "core/dom/custom/custom_element_registry.h"
 #include "core/dom/Document.h"
 #include "core/frame/Settings.h"
 #include "gen/sky/platform/RuntimeEnabledFeatures.h"
 #include "wtf/HashMap.h"
 
 namespace blink {
 
 using namespace {{namespace}}Names;
 
 typedef PassRefPtr<{{namespace}}Element> (*ConstructorFunction)(
@@ skipping 51 matching lines @@
     bool createdByParser)
 {
     if (!g_constructors)
         create{{namespace}}FunctionMap();
     if (ConstructorFunction function = g_constructors->get(localName))
         return function(document, createdByParser);
     return document.elementRegistry().CreateElement(document, localName);
 }
 
 } // namespace blink