Use Document::CreateRawElement instead of createElement.

If the first argument of createElement() is a pre-defined QualifiedName,
CreateRawElement() is less expensive.

This CL should not have user-visible behavior changes.

Bug: 806641
Change-Id: I80c96306031e83e1124882fcde456d54f762529f
Reviewed-on: https://chromium-review.googlesource.com/892601Reviewed-by: Hayato Ito <hayato@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532803}

third_party/WebKit/Source/core/dom/Document.h

@@ -343,7 +343,12 @@ class CORE_EXPORT Document : public ContainerNode,
   Element* createElementNS(const AtomicString& namespace_uri,
                            const AtomicString& qualified_name,
                            ExceptionState&);
+  // Creates an element with autonomous custom element processing. If
+  // LocalName of the specified qualified name doesn't contain '-', this
+  // function is equivalent to CreateRawElement().
   Element* createElement(const QualifiedName&, CreateElementFlags);
+  // Creates an element without custom element processing.
+  Element* CreateRawElement(const QualifiedName&, CreateElementFlags);
 
   Element* ElementFromPoint(double x, double y) const;
   HeapVector<Member<Element>> ElementsFromPoint(double x, double y) const;
@@ -1537,8 +1542,6 @@ class CORE_EXPORT Document : public ContainerNode,
   // the LocalFrameClient.
   void ApplyFeaturePolicy(const ParsedFeaturePolicy& declared_policy);
 
-  Element* CreateRawElement(const QualifiedName&, CreateElementFlags);
-
   DocumentLifecycle lifecycle_;
 
   bool has_nodes_with_placeholder_style_;

third_party/WebKit/Source/core/dom/events/EventPathTest.cpp

@@ -17,8 +17,8 @@ namespace blink {
 class EventPathTest : public PageTestBase {};
 
 TEST_F(EventPathTest, ShouldBeEmptyForPseudoElementWithoutParentElement) {
-  Element* div =
-      GetDocument().createElement(HTMLNames::divTag, kCreatedByCreateElement);
+  Element* div = GetDocument().CreateRawElement(HTMLNames::divTag,
+                                                kCreatedByCreateElement);
   PseudoElement* pseudo = PseudoElement::Create(div, kPseudoIdFirstLetter);
   pseudo->Dispose();
   EventPath event_path(*pseudo);

third_party/WebKit/Source/core/editing/testing/EditingTestBase.cpp

@@ -25,8 +25,8 @@ Element* GetOrCreateElement(ContainerNode* parent,
       tag_name.NamespaceURI(), tag_name.LocalName());
   if (!elements->IsEmpty())
     return elements->item(0);
-  return parent->ownerDocument()->createElement(tag_name,
-                                                kCreatedByCreateElement);
+  return parent->ownerDocument()->CreateRawElement(tag_name,
+                                                   kCreatedByCreateElement);
 }
 
 }  // namespace
@@ -38,8 +38,8 @@ EditingTestBase::~EditingTestBase() = default;
 void EditingTestBase::InsertStyleElement(const std::string& style_rules) {
   Element* const head = GetOrCreateElement(&GetDocument(), HTMLNames::headTag);
   DCHECK_EQ(head, GetOrCreateElement(&GetDocument(), HTMLNames::headTag));
-  Element* const style =
-      GetDocument().createElement(HTMLNames::styleTag, kCreatedByCreateElement);
+  Element* const style = GetDocument().CreateRawElement(
+      HTMLNames::styleTag, kCreatedByCreateElement);
   style->setTextContent(String(style_rules.data(), style_rules.size()));
   head->appendChild(style);
 }

third_party/WebKit/Source/core/html/forms/HTMLSelectElement.cpp

@@ -422,9 +422,7 @@ void HTMLSelectElement::setLength(unsigned new_len,
 
   if (diff < 0) {  // Add dummy elements.
     do {
-      AppendChild(
-          GetDocument().createElement(optionTag, kCreatedByCreateElement),
-          exception_state);
+      AppendChild(HTMLOptionElement::Create(GetDocument()), exception_state);
       if (exception_state.HadException())
         break;
     } while (++diff);

third_party/WebKit/Source/core/xml/parser/XMLErrors.cpp

@@ -97,7 +97,7 @@ void XMLErrors::AppendErrorMessage(const String& type_string,
 static inline Element* CreateXHTMLParserErrorHeader(
     Document* doc,
     const String& error_messages) {
-  Element* report_element = doc->createElement(
+  Element* report_element = doc->CreateRawElement(
       QualifiedName(g_null_atom, "parsererror", xhtmlNamespaceURI),
       kCreatedByParser);
 
@@ -108,12 +108,12 @@ static inline Element* CreateXHTMLParserErrorHeader(
       "1em 0 1em; margin: 1em; background-color: #fdd; color: black"));
   report_element->ParserSetAttributes(report_attributes);
 
-  Element* h3 = doc->createElement(h3Tag, kCreatedByParser);
+  Element* h3 = doc->CreateRawElement(h3Tag, kCreatedByParser);
   report_element->ParserAppendChild(h3);
   h3->ParserAppendChild(
       doc->createTextNode("This page contains the following errors:"));
 
-  Element* fixed = doc->createElement(divTag, kCreatedByParser);
+  Element* fixed = doc->CreateRawElement(divTag, kCreatedByParser);
   Vector<Attribute> fixed_attributes;
   fixed_attributes.push_back(
       Attribute(styleAttr, "font-family:monospace;font-size:12px"));
@@ -122,7 +122,7 @@ static inline Element* CreateXHTMLParserErrorHeader(
 
   fixed->ParserAppendChild(doc->createTextNode(error_messages));
 
-  h3 = doc->createElement(h3Tag, kCreatedByParser);
+  h3 = doc->CreateRawElement(h3Tag, kCreatedByParser);
   report_element->ParserAppendChild(h3);
   h3->ParserAppendChild(doc->createTextNode(
       "Below is a rendering of the page up to the first error."));
@@ -138,22 +138,24 @@ void XMLErrors::InsertErrorMessageBlock() {
   // Create elements for display
   Element* document_element = document_->documentElement();
   if (!document_element) {
-    Element* root_element = document_->createElement(htmlTag, kCreatedByParser);
-    Element* body = document_->createElement(bodyTag, kCreatedByParser);
+    Element* root_element =
+        document_->CreateRawElement(htmlTag, kCreatedByParser);
+    Element* body = document_->CreateRawElement(bodyTag, kCreatedByParser);
     root_element->ParserAppendChild(body);
     document_->ParserAppendChild(root_element);
     document_element = body;
   } else if (document_element->namespaceURI() == SVGNames::svgNamespaceURI) {
-    Element* root_element = document_->createElement(htmlTag, kCreatedByParser);
-    Element* head = document_->createElement(headTag, kCreatedByParser);
-    Element* style = document_->createElement(styleTag, kCreatedByParser);
+    Element* root_element =
+        document_->CreateRawElement(htmlTag, kCreatedByParser);
+    Element* head = document_->CreateRawElement(headTag, kCreatedByParser);
+    Element* style = document_->CreateRawElement(styleTag, kCreatedByParser);
     head->ParserAppendChild(style);
     style->ParserAppendChild(
         document_->createTextNode("html, body { height: 100% } parsererror + "
                                   "svg { width: 100%; height: 100% }"));
     style->FinishParsingChildren();
     root_element->ParserAppendChild(head);
-    Element* body = document_->createElement(bodyTag, kCreatedByParser);
+    Element* body = document_->CreateRawElement(bodyTag, kCreatedByParser);
     root_element->ParserAppendChild(body);
 
     document_->ParserRemoveChild(*document_element);
@@ -171,7 +173,7 @@ void XMLErrors::InsertErrorMessageBlock() {
   if (DocumentXSLT::HasTransformSourceDocument(*document_)) {
     Vector<Attribute> attributes;
     attributes.push_back(Attribute(styleAttr, "white-space: normal"));
-    Element* paragraph = document_->createElement(pTag, kCreatedByParser);
+    Element* paragraph = document_->CreateRawElement(pTag, kCreatedByParser);
     paragraph->ParserSetAttributes(attributes);
     paragraph->ParserAppendChild(document_->createTextNode(
         "This document was created as the result of an XSL transformation. The "