Make customElements.define faster

third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.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/CustomElementDefinition.h"
 
 #include "core/dom/Attr.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/custom/CustomElement.h"
 #include "core/dom/custom/CustomElementAdoptedCallbackReaction.h"
 #include "core/dom/custom/CustomElementAttributeChangedCallbackReaction.h"
 #include "core/dom/custom/CustomElementConnectedCallbackReaction.h"
 #include "core/dom/custom/CustomElementDisconnectedCallbackReaction.h"
 #include "core/dom/custom/CustomElementReaction.h"
 #include "core/dom/custom/CustomElementReactionStack.h"
 #include "core/dom/custom/CustomElementUpgradeReaction.h"
 #include "core/html/HTMLElement.h"
 
 namespace blink {
 
 CustomElementDefinition::CustomElementDefinition(
     const CustomElementDescriptor& descriptor)
     : descriptor_(descriptor) {}
 
 CustomElementDefinition::CustomElementDefinition(
     const CustomElementDescriptor& descriptor,
-    const HashSet<AtomicString>& observed_attributes)
+    HashSet<AtomicString>&& observed_attributes)
     : descriptor_(descriptor),
       observed_attributes_(observed_attributes),
       has_style_attribute_changed_callback_(
-          observed_attributes.Contains(HTMLNames::styleAttr.LocalName())) {}
+          observed_attributes_.Contains(HTMLNames::styleAttr.LocalName())) {}
 
 CustomElementDefinition::~CustomElementDefinition() {}
 
 DEFINE_TRACE(CustomElementDefinition) {
   visitor->Trace(construction_stack_);
 }
 
 static String ErrorMessageForConstructorResult(Element* element,
                                                Document& document,
                                                const QualifiedName& tag_name) {
@@ skipping 169 matching lines @@
     element->SynchronizeAttribute(name);
   for (const auto& attribute : element->AttributesWithoutUpdate()) {
     if (HasAttributeChangedCallback(attribute.GetName())) {
       EnqueueAttributeChangedCallback(element, attribute.GetName(), g_null_atom,
                                       attribute.Value());
     }
   }
 }
 
 }  // namespace blink