Add Document::CreateRawElement(), and use it in some functions.

The purpose of this function is to reduce the number of callsites for
FooElementFactory::createFooElement(), which don't support prefixes
correctly and contain unnecessary custom element processing.

The implementation of CreateRawElement() is equivalent to
Document::createElement(qname, flags) without custom-element processing.

* Document::createElement(local_name, options, exception_state):
  Replace createElement(local_name, exception_state) with
  CreateRawElement(). createElement(local_name, exception_state)
  contains V0 custom-element processing, but it isn't necessary here
  because it's already done before calling createElement().

* Document::createElementNS(ns, qname, exception_state):
  Replace createElement(qname, flag) call with V0 custom-element
  processing and CreateRawElement().
  createElement(qname, flag) does V0 custom-element processing in this
  path. This CL adds the custom-element processing here, and use
  CreateRawElement().

* Document::createElementNS(ns, qname, options, exception_state):
  Replace createElement(qname, flag) call with CreateRawElement().
  createElement(qname, flag) contains V0 custom-element processing,
  but it isn't necessary here because it's already done before
  calling createElement().

Bug: 806641
Change-Id: Ib3d0f3e8cc05b17c69945594b307d76988a840ea
Reviewed-on: https://chromium-review.googlesource.com/890958Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532366}

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

@@ -146,6 +146,7 @@
 #include "core/html/HTMLScriptElement.h"
 #include "core/html/HTMLTemplateElement.h"
 #include "core/html/HTMLTitleElement.h"
+#include "core/html/HTMLUnknownElement.h"
 #include "core/html/PluginDocument.h"
 #include "core/html/WindowNameCollection.h"
 #include "core/html/canvas/CanvasContextCreationAttributes.h"
@@ -211,6 +212,7 @@
 #include "core/svg/SVGDocumentExtensions.h"
 #include "core/svg/SVGScriptElement.h"
 #include "core/svg/SVGTitleElement.h"
+#include "core/svg/SVGUnknownElement.h"
 #include "core/svg/SVGUseElement.h"
 #include "core/svg_element_factory.h"
 #include "core/svg_names.h"
@@ -853,6 +855,38 @@ AtomicString Document::ConvertLocalName(const AtomicString& name) {
   return IsHTMLDocument() ? name.LowerASCII() : name;
 }
 
+// Just creates an element with specified qualified name without any
+// custom element processing.
+// This is a common code for step 5.2 and 7.2 of "create an element"
+// <https://dom.spec.whatwg.org/#concept-create-element>
+// Functions other than this one should not use HTMLElementFactory and
+// SVGElementFactory because they don't support prefixes correctly.
+Element* Document::CreateRawElement(const QualifiedName& qname,
+                                    CreateElementFlags flags) {
+  Element* element = nullptr;
+  if (qname.NamespaceURI() == HTMLNames::xhtmlNamespaceURI) {
+    element = HTMLElementFactory::CreateRawHTMLElement(qname.LocalName(), *this,
+                                                       flags);
+    if (!element)
+      element = HTMLUnknownElement::Create(qname, *this);
+    saw_elements_in_known_namespaces_ = true;
+  } else if (qname.NamespaceURI() == SVGNames::svgNamespaceURI) {
+    element =
+        SVGElementFactory::CreateRawSVGElement(qname.LocalName(), *this, flags);
+    if (!element)
+      element = SVGUnknownElement::Create(qname, *this);
+    saw_elements_in_known_namespaces_ = true;
+  } else {
+    element = Element::Create(qname, this);
+  }
+
+  if (element->prefix() != qname.Prefix())
+    element->SetTagNameForCreateElementNS(qname);
+  DCHECK(qname == element->TagQName());
+
+  return element;
+}
+
 // https://dom.spec.whatwg.org/#dom-document-createelement
 Element* Document::createElement(const AtomicString& name,
                                  ExceptionState& exception_state) {
@@ -966,9 +1000,12 @@ Element* Document::createElement(const AtomicString& local_name,
         *this,
         QualifiedName(g_null_atom, converted_local_name, xhtmlNamespaceURI));
   } else {
-    element = createElement(local_name, exception_state);
-    if (exception_state.HadException())
-      return nullptr;
+    element =
+        CreateRawElement(QualifiedName(g_null_atom, converted_local_name,
+                                       IsXHTMLDocument() || IsHTMLDocument()
+                                           ? HTMLNames::xhtmlNamespaceURI
+                                           : g_null_atom),
+                         kCreatedByCreateElement);
   }
 
   // 8. If 'is' is non-null, set 'is' attribute
@@ -1016,7 +1053,10 @@ Element* Document::createElementNS(const AtomicString& namespace_uri,
 
   if (CustomElement::ShouldCreateCustomElement(q_name))
     return CustomElement::CreateCustomElementSync(*this, q_name);
-  return createElement(q_name, kCreatedByCreateElement);
+  else if (RegistrationContext() &&
+           V0CustomElement::IsValidName(q_name.LocalName()))
+    return RegistrationContext()->CreateCustomTagElement(*this, q_name);
+  return CreateRawElement(q_name, kCreatedByCreateElement);
 }
 
 // https://dom.spec.whatwg.org/#internal-createelementns-steps
@@ -1076,7 +1116,7 @@ Element* Document::createElementNS(const AtomicString& namespace_uri,
              RegistrationContext()) {
     element = RegistrationContext()->CreateCustomTagElement(*this, q_name);
   } else {
-    element = createElement(q_name, kCreatedByCreateElement);
+    element = CreateRawElement(q_name, kCreatedByCreateElement);
   }
 
   // 6. If 'is' is non-null, set 'is' attribute

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

@@ -1537,6 +1537,8 @@ 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_;