Introduce CustomElementRegistry#get() method

third_party/WebKit/Source/bindings/core/v8/ScriptCustomElementDefinition.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 ScriptCustomElementDefinition_h
 #define ScriptCustomElementDefinition_h
 
 #include "bindings/core/v8/ScopedPersistent.h"
 #include "core/CoreExport.h"
 #include "core/dom/custom/CustomElementDefinition.h"
@@ skipping 27 matching lines @@
     v8::Local<v8::Object> constructor(ScriptState*) const;
     v8::Local<v8::Object> prototype(ScriptState*) const;
 
 private:
     ScriptCustomElementDefinition(
         ScriptState*,
         const CustomElementDescriptor&,
         const v8::Local<v8::Object>& constructor,
         const v8::Local<v8::Object>& prototype);
 
+    // Implementations of |CustomElementDefinition|
+    ScriptValue getConstructor(ScriptState*) final;

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

Because ScriptCustomElementDefinition will need to vend callbacks, I think it
should have RefPtr<ScriptState> and simply use that.

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

We should have |ScriptState*| here to verify we use |SCE| with valid context.

+
     ScopedPersistent<v8::Object> m_constructor;
     ScopedPersistent<v8::Object> m_prototype;
 };
 
 } // namespace blink
 
 #endif // ScriptCustomElementDefinition_h