Introduce CustomElementRegistry#get() method

third_party/WebKit/Source/bindings/core/v8/ScriptCustomElementDefinition.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 "bindings/core/v8/ScriptCustomElementDefinition.h"
 
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/V8Binding.h"
 #include "bindings/core/v8/V8CustomElementsRegistry.h"
 #include "bindings/core/v8/V8HiddenValue.h"
@@ skipping 91 matching lines @@
 
     return definition;
 }
 
 ScriptCustomElementDefinition::ScriptCustomElementDefinition(
     ScriptState* scriptState,
     const CustomElementDescriptor& descriptor,
     const v8::Local<v8::Object>& constructor,
     const v8::Local<v8::Object>& prototype)
     : CustomElementDefinition(descriptor)
+    , m_scriptState(scriptState)
     , m_constructor(scriptState->isolate(), constructor)
     , m_prototype(scriptState->isolate(), prototype)
 {
     // These objects are kept alive by references from the
     // CustomElementsRegistry wrapper set up by
     // ScriptCustomElementDefinition::create.
     m_constructor.setPhantom();
     m_prototype.setPhantom();
 }
 
 v8::Local<v8::Object> ScriptCustomElementDefinition::constructor(
     ScriptState* scriptState) const
 {
+    DCHECK_EQ(m_scriptState, scriptState);
     DCHECK(!m_constructor.isEmpty());
     return m_constructor.newLocal(scriptState->isolate());
 }
 
 v8::Local<v8::Object> ScriptCustomElementDefinition::prototype(
     ScriptState* scriptState) const
 {
+    DCHECK_EQ(m_scriptState, scriptState);

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

Do we really need to have this check?

     DCHECK(!m_prototype.isEmpty());
     return m_prototype.newLocal(scriptState->isolate());
 }
 
+// CustomElementDefinition
+ScriptValue ScriptCustomElementDefinition::getConstructor(
+    ScriptState* scriptState)
+{
+    if (m_scriptState != scriptState)

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

Do we really need to have this check?

+        return ScriptValue(scriptState, v8Undefined());

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

Should be |ScriptValue()|

[dominicc (has gone to gerrit), 2016/05/31 22:56:32]

Why not just do that?

[yosin_UTC9, 2016/06/01 02:14:37]

I expect to have this patch isn't ready for commit or first round of review.
I decided to fix in next round.

Done.

+    return ScriptValue(scriptState, constructor(scriptState));
+}
+
 } // namespace blink