Re-land: Don't keep recreating AXMenuListPopup

Source/modules/accessibility/AXObjectCacheImpl.cpp

 /*
  * Copyright (C) 2014, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 185 matching lines @@
         return 0;
 
     AXID axID = m_layoutObjectMapping.get(layoutObject);
     ASSERT(!HashTraits<AXID>::isDeletedValue(axID));
     if (!axID)
         return 0;
 
     return m_objects.get(axID);
 }
 
+// Returns true if |node| is an <option> element and its parent <select>
+// is a menu list (not a list box).
+static bool isMenuListOption(Node* node)
+{
+    if (!isHTMLOptionElement(node))
+        return false;
+    Element* parent = node->parentElement();
+    if (isHTMLOptGroupElement(parent))
+        parent = parent->parentElement();
+    if (!isHTMLSelectElement(parent))
+        return false;
+    LayoutObject* layoutObject = toHTMLSelectElement(parent)->layoutObject();
+    return layoutObject && layoutObject->isMenuList();
+}
+
 AXObject* AXObjectCacheImpl::get(Node* node)
 {
     if (!node)
         return 0;
 
     AXID layoutID = node->layoutObject() ? m_layoutObjectMapping.get(node->layoutObject()) : 0;
     ASSERT(!HashTraits<AXID>::isDeletedValue(layoutID));
 
     AXID nodeID = m_nodeObjectMapping.get(node);
     ASSERT(!HashTraits<AXID>::isDeletedValue(nodeID));
 
-    if (node->layoutObject() && nodeID && !layoutID) {
+    if (node->layoutObject() && nodeID && !layoutID && !isMenuListOption(node)) {
         // This can happen if an AXNodeObject is created for a node that's not
         // laid out, but later something changes and it gets a layoutObject (like if it's
         // reparented).
         remove(nodeID);
         return 0;
     }
 
     if (layoutID)
         return m_objects.get(layoutID);
 
@@ skipping 77 matching lines @@
         // input type=range
         if (cssBox->isSlider())
             return AXSlider::create(toLayoutSlider(cssBox), this);
     }
 
     return AXLayoutObject::create(layoutObject, this);
 }
 
 PassRefPtr<AXObject> AXObjectCacheImpl::createFromNode(Node* node)
 {
+    if (isMenuListOption(node))
+        return AXMenuListOption::create(toHTMLOptionElement(node), this);
+
     return AXNodeObject::create(node, this);
 }
 
 PassRefPtr<AXObject> AXObjectCacheImpl::createFromInlineTextBox(AbstractInlineTextBox* inlineTextBox)
 {
     return AXInlineTextBox::create(inlineTextBox, this);
 }
 
 AXObject* AXObjectCacheImpl::getOrCreate(Widget* widget)
 {
@@ skipping 36 matching lines @@
     if (node->layoutObject())
         return getOrCreate(node->layoutObject());
 
     if (!node->parentElement())
         return 0;
 
     // It's only allowed to create an AXObject from a Node if it's in a canvas subtree.
     // Or if it's a hidden element, but we still want to expose it because of other ARIA attributes.
     bool inCanvasSubtree = node->parentElement()->isInCanvasSubtree();
     bool isHidden = !node->layoutObject() && isNodeAriaVisible(node);
-    if (!inCanvasSubtree && !isHidden)
+    if (!inCanvasSubtree && !isHidden && !isMenuListOption(node))
         return 0;
 
     RefPtr<AXObject> newObj = createFromNode(node);
 
     // Will crash later if we have two objects for the same node.
     ASSERT(!get(node));
 
     getAXID(newObj.get());
 
     m_nodeObjectMapping.set(node, newObj->axObjectID());
@@ skipping 72 matching lines @@
         break;
     case TableHeaderContainerRole:
         obj = AXTableHeaderContainer::create(this);
         break;
     case SliderThumbRole:
         obj = AXSliderThumb::create(this);
         break;
     case MenuListPopupRole:
         obj = AXMenuListPopup::create(this);
         break;
-    case MenuListOptionRole:
-        obj = AXMenuListOption::create(this);
-        break;
     case SpinButtonRole:
         obj = AXSpinButton::create(this);
         break;
     case SpinButtonPartRole:
         obj = AXSpinButtonPart::create(this);
         break;
     default:
         obj = nullptr;
     }
 
@@ skipping 648 matching lines @@
 void AXObjectCacheImpl::setCanvasObjectBounds(Element* element, const LayoutRect& rect)
 {
     AXObject* obj = getOrCreate(element);
     if (!obj)
         return;
 
     obj->setElementRect(rect);
 }
 
 } // namespace blink