Split custom element script use and move it into bindings

third_party/WebKit/Source/core/dom/custom/CustomElementDefinitionBuilder.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CustomElementDefinitionBuilder_h
+#define CustomElementDefinitionBuilder_h
+
+#include "core/CoreExport.h"
+#include "wtf/Allocator.h"
+#include "wtf/Noncopyable.h"
+
+namespace blink {
+
+class CustomElementDefinition;
+class CustomElementDescriptor;
+class CustomElementsRegistry;
+class ExceptionState;
+class ScriptState;
+class ScriptValue;
+
+// Implement CustomElementDefinitionBuilder to provide
+// technology-specific steps for CustomElementsRegistry.define.
+// https://html.spec.whatwg.org/multipage/scripting.html#dom-customelementsregistry-define
+class CORE_EXPORT CustomElementDefinitionBuilder {
+    STACK_ALLOCATED();
+    WTF_MAKE_NONCOPYABLE(CustomElementDefinitionBuilder);
+public:
+    CustomElementDefinitionBuilder() { }
+
+    // This API necessarily sounds JavaScript specific; this implements
+    // some steps of the CustomElementsRegistry.define process, which
+    // are defined in terms of JavaScript.
+
+    // Check the constructor is valid. Return false if processing
+    // should not proceed.
+    virtual bool checkConstructorIntrinsics() = 0;
+
+    // Check the constructor is not already registered in the calling
+    // registry. Return false if processing should not proceed.
+    virtual bool checkConstructorNotRegistered() = 0;
+
+    // Checking the prototype may destroy the window. Return false if
+    // processing should not proceed.
+    virtual bool checkPrototype() = 0;
+
+    // Produce the definition. This must produce a definition.
+    virtual CustomElementDefinition* build(const CustomElementDescriptor&) = 0;
+};
+
+} // namespace blink
+
+#endif // CustomElementDefinitionBuilder_h