Make customElements.define faster

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 "bindings/core/v8/ScriptState.h"
+#include "bindings/core/v8/TraceWrapperV8Reference.h"
 #include "core/CoreExport.h"
 #include "core/dom/custom/CustomElementDefinition.h"
 #include "platform/wtf/Noncopyable.h"
 #include "platform/wtf/RefPtr.h"
 #include "v8.h"
 
 namespace blink {
 
 class CustomElementDescriptor;
 class CustomElementRegistry;
 
 class CORE_EXPORT ScriptCustomElementDefinition final
     : public CustomElementDefinition {
   WTF_MAKE_NONCOPYABLE(ScriptCustomElementDefinition);
 
  public:
   static ScriptCustomElementDefinition* ForConstructor(
       ScriptState*,
       CustomElementRegistry*,
       const v8::Local<v8::Value>& constructor);
 
   static ScriptCustomElementDefinition* Create(
       ScriptState*,
       CustomElementRegistry*,
       const CustomElementDescriptor&,
+      CustomElementDefinition::Id,
       const v8::Local<v8::Object>& constructor,
       const v8::Local<v8::Function>& connected_callback,
       const v8::Local<v8::Function>& disconnected_callback,
       const v8::Local<v8::Function>& adopted_callback,
       const v8::Local<v8::Function>& attribute_changed_callback,
       const HashSet<AtomicString>& observed_attributes);
 
   virtual ~ScriptCustomElementDefinition() = default;
 
+  DECLARE_VIRTUAL_TRACE_WRAPPERS();
+
   v8::Local<v8::Object> Constructor() const;
 
   HTMLElement* CreateElementSync(Document&, const QualifiedName&) override;
 
   bool HasConnectedCallback() const override;
   bool HasDisconnectedCallback() const override;
   bool HasAdoptedCallback() const override;
 
   void RunConnectedCallback(Element*) override;
   void RunDisconnectedCallback(Element*) override;
@@ skipping 27 matching lines @@
                    Element*,
                    int argc = 0,
                    v8::Local<v8::Value> argv[] = nullptr);
 
   HTMLElement* HandleCreateElementSyncException(Document&,
                                                 const QualifiedName& tag_name,
                                                 v8::Isolate*,
                                                 ExceptionState&);
 
   RefPtr<ScriptState> script_state_;
-  ScopedPersistent<v8::Object> constructor_;
-  ScopedPersistent<v8::Function> connected_callback_;
-  ScopedPersistent<v8::Function> disconnected_callback_;
-  ScopedPersistent<v8::Function> adopted_callback_;
-  ScopedPersistent<v8::Function> attribute_changed_callback_;
+  // TODO(dominicc): Change these to Object, Function respectively
+  // when TraceWrappers supports more than just v8::Value.
+  TraceWrapperV8Reference<v8::Value> constructor_;

[Michael Lippautz, 2017/04/19 08:49:12]

The intention of the template was that you can keep your specific types here and
use e.g. connected_callback.Cast<v8::Value>() in the tracing function. (see
below).

+  TraceWrapperV8Reference<v8::Value> connected_callback_;
+  TraceWrapperV8Reference<v8::Value> disconnected_callback_;
+  TraceWrapperV8Reference<v8::Value> adopted_callback_;
+  TraceWrapperV8Reference<v8::Value> attribute_changed_callback_;
 };
 
 }  // namespace blink
 
 #endif  // ScriptCustomElementDefinition_h