MenuList SELECT: Update text in the shadow element

When UpdateFromElement() is called, textContent of the shadow element
should be updated as well as the text in the anonymous block.
Exceptions:
 * In DidStyleRecalc() and AttachLayoutTree(), we must not update DOM
   at all.
 * Instead, we should update the textContent
  - when the UA shadow tree is created, or
  - even if the SELECT has no LayoutObject

This CL has no user-visible behavior changes because the shadow element
has display:none.

Bug: 1040828
Change-Id: I55f0bfd0399ca50a8aa99c64a8fdf89ef5c42e68
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2032656Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737652}

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

@@ -368,9 +368,9 @@ void HTMLSelectElement::OptionElementChildrenChanged(
     const HTMLOptionElement& option) {
   SetNeedsValidityCheck();
 
+  if (option.Selected() && UsesMenuList())
+    UpdateMenuListLabel(UpdateFromElement());
   if (GetLayoutObject()) {
-    if (option.Selected() && UsesMenuList())
-      UpdateFromElement();
     if (AXObjectCache* cache =
             GetLayoutObject()->GetDocument().ExistingAXObjectCache())
       cache->ChildrenChanged(this);
@@ -916,10 +916,9 @@ void HTMLSelectElement::SetSuggestedOption(HTMLOptionElement* option) {
     return;
   suggested_option_ = option;
 
-  if (GetLayoutObject()) {
-    UpdateFromElement();
+  UpdateMenuListLabel(UpdateFromElement());
+  if (GetLayoutObject())
     ScrollToOption(option);
-  }
   if (PopupIsVisible())
     popup_->UpdateFromElement(PopupMenu::kBySelectionChange);
 }
@@ -1093,7 +1092,7 @@ void HTMLSelectElement::SelectOption(HTMLOptionElement* element,
   }
 
   // For the menu list case, this is what makes the selected element appear.
-  UpdateFromElement();
+  UpdateMenuListLabel(UpdateFromElement());
   // PopupMenu::UpdateFromElement() posts an O(N) task.
   if (PopupIsVisible() && should_update_popup)
     popup_->UpdateFromElement(PopupMenu::kBySelectionChange);
@@ -2010,6 +2009,7 @@ void HTMLSelectElement::UpdateUserAgentShadowTree(ShadowRoot& root) {
   if (UsesMenuList()) {
     root.insertBefore(MakeGarbageCollected<MenuListInnerElement>(GetDocument()),
                       root.firstChild());
+    UpdateMenuListLabel(UpdateFromElement());
   }
 }
 
@@ -2077,7 +2077,7 @@ void HTMLSelectElement::PopupDidHide() {
 
 void HTMLSelectElement::SetIndexToSelectOnCancel(int list_index) {
   index_to_select_on_cancel_ = list_index;
-  UpdateFromElement();
+  UpdateMenuListLabel(UpdateFromElement());
 }
 
 HTMLOptionElement* HTMLSelectElement::OptionToBeShown() const {
@@ -2291,12 +2291,9 @@ void HTMLSelectElement::ChangeRendering() {
   }
 }
 
-void HTMLSelectElement::UpdateFromElement() {
+String HTMLSelectElement::UpdateFromElement() {
   if (!UsesMenuList())
-    return;
-  auto* layout_object = GetLayoutObject();
-  if (!layout_object)
-    return;
+    return String();
 
   HTMLOptionElement* option = OptionToBeShown();
   String text = g_empty_string;
@@ -2330,9 +2327,18 @@ void HTMLSelectElement::UpdateFromElement() {
     }
   }
 
-  ToLayoutMenuList(layout_object)->SetText(text.StripWhiteSpace());
-  layout_object->UpdateFromElement();
-  DidUpdateMenuListActiveOption(option);
+  String stripped = text.StripWhiteSpace();
+  if (auto* layout_object = GetLayoutObject()) {
+    ToLayoutMenuList(layout_object)->SetText(stripped);
+    layout_object->UpdateFromElement();
+    DidUpdateMenuListActiveOption(option);
+  }
+  return stripped;
+}
+
+void HTMLSelectElement::UpdateMenuListLabel(const String& label) {
+  if (UsesMenuList())
+    InnerElement().setTextContent(label);
 }
 
 const ComputedStyle* HTMLSelectElement::OptionStyle() const {

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

@@ -186,7 +186,10 @@ class CORE_EXPORT HTMLSelectElement final
 
  private:
   const AtomicString& FormControlType() const override;
-  void UpdateFromElement();
+  // Update style on style or selected OPTION change, and return text to be
+  // shown.
+  String UpdateFromElement();
+  void UpdateMenuListLabel(const String& label);
 
   bool MayTriggerVirtualKeyboard() const override;
 

third_party/blink/web_tests/fast/forms/suggested-value-after-empty-suggested-value-expected.txt

@@ -155,6 +155,7 @@ Input after setting suggestedValue:
 |       "TX"
 |   <shadow:root>
 |     <div>
+|       "TX"
 |     <slot>
 |       name="user-agent-custom-assign-slot"
 | "input.value: initial value"

third_party/blink/web_tests/fast/forms/suggested-value-expected.txt

@@ -91,6 +91,7 @@ instead of "initial value".
 |       "inserted value"
 |   <shadow:root>
 |     <div>
+|       "initial value"
 |     <slot>
 |       name="user-agent-custom-assign-slot"
 | "input.value: initial value"

third_party/blink/web_tests/inspector-protocol/dom-snapshot/dom-snapshot-getSnapshot-input-value-expected.txt

@@ -43,7 +43,7 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "childNodeIndexes": [
         4,
         5,
-        34
+        35
       ],
       "attributes": [
         {
@@ -67,11 +67,10 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "childNodeIndexes": [
         6,
         7,
-        14,
         15,
-        18,
+        16,
         19,
-        21,
+        20,
         22,
         23,
         24,
@@ -81,7 +80,8 @@ Tests DOMSnapshot.getSnapshot method returning input values.
         28,
         29,
         30,
-        33
+        31,
+        34
       ],
       "attributes": [
         {
@@ -104,7 +104,7 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "backendNodeId": "<number>",
       "childNodeIndexes": [
         8,
-        9
+        10
       ],
       "layoutNodeIndex": 4
     },
@@ -113,6 +113,16 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "nodeName": "DIV",
       "nodeValue": "",
       "backendNodeId": "<number>",
+      "childNodeIndexes": [
+        9
+      ],
+      "shadowRootType": "user-agent"
+    },
+    {
+      "nodeType": 3,
+      "nodeName": "#text",
+      "nodeValue": "Option 1",
+      "backendNodeId": "<number>",
       "shadowRootType": "user-agent"
     },
     {
@@ -121,8 +131,8 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "nodeValue": "",
       "backendNodeId": "<number>",
       "childNodeIndexes": [
-        10,
-        12
+        11,
+        13
       ],
       "attributes": [
         {
@@ -139,7 +149,7 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "optionSelected": true,
       "backendNodeId": "<number>",
       "childNodeIndexes": [
-        11
+        12
       ],
       "attributes": [
         {
@@ -162,7 +172,7 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "optionSelected": false,
       "backendNodeId": "<number>",
       "childNodeIndexes": [
-        13
+        14
       ],
       "attributes": [
         {
@@ -192,7 +202,7 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "inputValue": "InputValue",
       "backendNodeId": "<number>",
       "childNodeIndexes": [
-        16
+        17
       ],
       "attributes": [
         {
@@ -213,7 +223,7 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "nodeValue": "",
       "backendNodeId": "<number>",
       "childNodeIndexes": [
-        17
+        18
       ],
       "layoutNodeIndex": 7,
       "shadowRootType": "user-agent",
@@ -242,7 +252,7 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "inputValue": "ButtonValue",
       "backendNodeId": "<number>",
       "childNodeIndexes": [
-        20
+        21
       ],
       "attributes": [
         {
@@ -411,7 +421,7 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "textValue": "TextAreaValue",
       "backendNodeId": "<number>",
       "childNodeIndexes": [
-        31
+        32
       ],
       "attributes": [
         {
@@ -427,7 +437,7 @@ Tests DOMSnapshot.getSnapshot method returning input values.
       "nodeValue": "",
       "backendNodeId": "<number>",
       "childNodeIndexes": [
-        32
+        33
       ],
       "layoutNodeIndex": 22,
       "shadowRootType": "user-agent",

third_party/blink/web_tests/platform/win/fast/forms/suggested-value-expected.txt

@@ -82,6 +82,7 @@ instead of "initial value".
 |       "inserted value"
 |   <shadow:root>
 |     <div>
+|       "initial value"
 |     <slot>
 |       name="user-agent-custom-assign-slot"
 | "input.value: initial value"

third_party/blink/web_tests/virtual/form-controls-refresh-disabled/fast/forms/suggested-value-expected.txt

@@ -91,6 +91,7 @@ instead of "initial value".
 |       "inserted value"
 |   <shadow:root>
 |     <div>
+|       "initial value"
 |     <slot>
 |       name="user-agent-custom-assign-slot"
 | "input.value: initial value"