Introduce CustomElementRegistry#get() method

third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.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 CustomElementDefinition_h
 #define CustomElementDefinition_h
 
 #include "core/CoreExport.h"
 #include "core/dom/custom/CustomElementDescriptor.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Noncopyable.h"
 
 namespace blink {
 
+class ScriptState;
+class ScriptValue;

[dominicc (has gone to gerrit), 2016/05/31 06:01:50]

Is it possible to return by value without a complete definition?

[yosin_UTC9, 2016/05/31 09:16:57]

It works, but users of CED needs to include "ScriptValue.h". I changed to add
#include "ScriptValue.h" here.

+
 class CORE_EXPORT CustomElementDefinition
     : public GarbageCollectedFinalized<CustomElementDefinition> {
     WTF_MAKE_NONCOPYABLE(CustomElementDefinition);
 public:
     CustomElementDefinition(const CustomElementDescriptor&);
     virtual ~CustomElementDefinition();
 
     const CustomElementDescriptor& descriptor() { return m_descriptor; }
 
+    virtual ScriptValue getConstructor(ScriptState*) = 0;

[dominicc (has gone to gerrit), 2016/05/31 06:01:51]

Write a C++ unit test that exercises this.

[yosin_UTC9, 2016/05/31 09:16:57]

Since, getConstructor() is used for implementing CER.get() and it is tested by
layout test.

Writing C++ test for getConstructor() is heavy, since it requires lots of thing,
e.g. DummyPageHolder to have ScriptCER, evaluate script to get constructor.
So, I would like to postpone having C++ test until we have script-free version
of getConstructor().

+
     DEFINE_INLINE_VIRTUAL_TRACE() { }
 
 private:
     const CustomElementDescriptor m_descriptor;
 };
 
 } // namespace blink
 
 #endif // CustomElementDefinition_h