Move the content of UpdateUserAgentShadowTree() and InnerElement()

... from HTMLSelectElement to MenuListSelectType.

This CL has no behavior changes.

Bug: 1052232
Change-Id: Id8d0725cfce3f3421681a62b180760ab48d430cc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2228280
Commit-Queue: Koji Ishii <kojii@chromium.org>
Auto-Submit: Kent Tamura <tkent@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774984}

third_party/blink/renderer/core/html/forms/html_select_element.cc

@@ -50,7 +50,6 @@
 #include "third_party/blink/renderer/core/html/forms/html_form_element.h"
 #include "third_party/blink/renderer/core/html/forms/html_opt_group_element.h"
 #include "third_party/blink/renderer/core/html/forms/html_option_element.h"
-#include "third_party/blink/renderer/core/html/forms/menu_list_inner_element.h"
 #include "third_party/blink/renderer/core/html/forms/select_type.h"
 #include "third_party/blink/renderer/core/html/html_hr_element.h"
 #include "third_party/blink/renderer/core/html/html_slot_element.h"
@@ -1196,21 +1195,11 @@ void HTMLSelectElement::UpdateUserAgentShadowTree(ShadowRoot& root) {
       will_be_removed->remove();
     }
   }
-  if (UsesMenuList()) {
-    Element* inner_element =
-        MakeGarbageCollected<MenuListInnerElement>(GetDocument());
-    inner_element->setAttribute(html_names::kAriaHiddenAttr, "true");
-    // Make sure InnerElement() always has a Text node.
-    inner_element->appendChild(Text::Create(GetDocument(), g_empty_string));
-    root.insertBefore(inner_element, root.firstChild());
-  }
+  select_type_->CreateShadowSubtree(root);
 }
 
 Element& HTMLSelectElement::InnerElement() const {
-  DCHECK(UsesMenuList());
-  auto* inner_element = DynamicTo<Element>(UserAgentShadowRoot()->firstChild());
-  DCHECK(inner_element);
-  return *inner_element;
+  return select_type_->InnerElement();
 }
 
 HTMLOptionElement* HTMLSelectElement::SpatialNavigationFocusedOption() {

third_party/blink/renderer/core/html/forms/select_type.cc

@@ -36,6 +36,7 @@
 #include "third_party/blink/renderer/core/dom/mutation_observer.h"
 #include "third_party/blink/renderer/core/dom/mutation_record.h"
 #include "third_party/blink/renderer/core/dom/node_computed_style.h"
+#include "third_party/blink/renderer/core/dom/text.h"
 #include "third_party/blink/renderer/core/events/gesture_event.h"
 #include "third_party/blink/renderer/core/events/keyboard_event.h"
 #include "third_party/blink/renderer/core/events/mouse_event.h"
@@ -43,6 +44,7 @@
 #include "third_party/blink/renderer/core/frame/local_frame.h"
 #include "third_party/blink/renderer/core/html/forms/html_form_element.h"
 #include "third_party/blink/renderer/core/html/forms/html_select_element.h"
+#include "third_party/blink/renderer/core/html/forms/menu_list_inner_element.h"
 #include "third_party/blink/renderer/core/html/forms/popup_menu.h"
 #include "third_party/blink/renderer/core/input/event_handler.h"
 #include "third_party/blink/renderer/core/input/input_device_capabilities.h"
@@ -92,6 +94,8 @@ class MenuListSelectType final : public SelectType {
   }
   void MaximumOptionWidthMightBeChanged() const override;
 
+  void CreateShadowSubtree(ShadowRoot& root) override;
+  Element& InnerElement() const override;
   void ShowPopup() override;
   void HidePopup() override;
   void PopupDidHide() override;
@@ -292,6 +296,22 @@ bool MenuListSelectType::HandlePopupOpenKeyboardEvent() {
   return true;
 }
 
+void MenuListSelectType::CreateShadowSubtree(ShadowRoot& root) {
+  Document& doc = select_->GetDocument();
+  Element* inner_element = MakeGarbageCollected<MenuListInnerElement>(doc);
+  inner_element->setAttribute(html_names::kAriaHiddenAttr, "true");
+  // Make sure InnerElement() always has a Text node.
+  inner_element->appendChild(Text::Create(doc, g_empty_string));
+  root.insertBefore(inner_element, root.firstChild());
+}
+
+Element& MenuListSelectType::InnerElement() const {
+  auto* inner_element =
+      DynamicTo<Element>(select_->UserAgentShadowRoot()->firstChild());
+  DCHECK(inner_element);
+  return *inner_element;
+}
+
 void MenuListSelectType::ShowPopup() {
   if (PopupIsVisible())
     return;
@@ -1308,6 +1328,15 @@ void SelectType::ListBoxOnChange() {}
 
 void SelectType::ClearLastOnChangeSelection() {}
 
+void SelectType::CreateShadowSubtree(ShadowRoot& root) {}
+
+Element& SelectType::InnerElement() const {
+  NOTREACHED();
+  // Returning select_ doesn't make sense, but we need to return an element
+  // to compile this source. This function must not be called.
+  return *select_;
+}
+
 void SelectType::ShowPopup() {
   NOTREACHED();
 }

third_party/blink/renderer/core/html/forms/select_type.h

@@ -58,6 +58,8 @@ class SelectType : public GarbageCollected<SelectType> {
   // This is for ListBoxes.
   virtual void ClearLastOnChangeSelection();
 
+  virtual void CreateShadowSubtree(ShadowRoot& root);
+  virtual Element& InnerElement() const;
   virtual void ShowPopup();
   virtual void HidePopup();
   virtual void PopupDidHide();