Implement the script parts of custom element upgrade steps.

third_party/WebKit/Source/core/dom/custom/CustomElementsRegistryTest.cpp

 // 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.
 
 #include "core/dom/custom/CustomElementsRegistry.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/ElementRegistrationOptions.h"
@@ skipping 218 matching lines @@
     }
 
     ~TestCustomElementDefinition() override = default;
 
     bool runConstructor(Element* element) override
     {
         if (constructionStack().isEmpty()
             || constructionStack().last() != element)
             return false;
         constructionStack().last().clear();
+        element->setCustomElementState(CustomElementState::Custom);
         return true;
     }
 };
 
 // Classes which use trace macros cannot be local because of the
 // traceImpl template.
 class LogUpgradeDefinition : public TestCustomElementDefinition {
     WTF_MAKE_NONCOPYABLE(LogUpgradeDefinition);
 public:
     LogUpgradeDefinition(const CustomElementDescriptor& descriptor)
@@ skipping 54 matching lines @@
     EXPECT_EQ(1u, definition->m_invocationCount)
         << "defining the element should have 'upgraded' the existing element";
     EXPECT_EQ(element, definition->m_element)
         << "the existing a-a element should have been upgraded";
 }
 
 // TODO(dominicc): Add tests which adjust the "is" attribute when type
 // extensions are implemented.
 
 } // namespace blink