Implement the inert attribute

third_party/WebKit/Source/modules/accessibility/AXObject.cpp

Index: third_party/WebKit/Source/modules/accessibility/AXObject.cpp
diff --git a/third_party/WebKit/Source/modules/accessibility/AXObject.cpp b/third_party/WebKit/Source/modules/accessibility/AXObject.cpp
index 6f074286088b6063a842fdcb80589590306b4608..a75d1700ec46e141b92b858a3f36f5a6c1bed8a4 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXObject.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXObject.cpp
@@ -536,10 +536,14 @@ bool AXObject::computeIsInertOrAriaHidden(
             ignoredReasons->push_back(
                 IgnoredReason(AXActiveModalDialog, dialogObject));
           else
-            ignoredReasons->push_back(IgnoredReason(AXInert));
+            ignoredReasons->push_back(IgnoredReason(AXInertElement));
         } else {
-          // TODO(aboxhall): handle inert attribute if it eventuates
-          ignoredReasons->push_back(IgnoredReason(AXInert));
+          const AXObject* inertRoot = this->inertRoot();
+          if (inertRoot == this) {
+            ignoredReasons->push_back(IgnoredReason(AXInertElement));
+          } else {
+            ignoredReasons->push_back(IgnoredReason(AXInertSubtree, inertRoot));
+          }
         }
       }
       return true;
@@ -556,10 +560,12 @@ bool AXObject::computeIsInertOrAriaHidden(
   const AXObject* hiddenRoot = ariaHiddenRoot();
   if (hiddenRoot) {
     if (ignoredReasons) {
-      if (hiddenRoot == this)
-        ignoredReasons->push_back(IgnoredReason(AXAriaHidden));
-      else
-        ignoredReasons->push_back(IgnoredReason(AXAriaHiddenRoot, hiddenRoot));
+      if (hiddenRoot == this) {
+        ignoredReasons->push_back(IgnoredReason(AXAriaHiddenElement));
+      } else {
+        ignoredReasons->push_back(
+            IgnoredReason(AXAriaHiddenSubtree, hiddenRoot));
+      }
     }
     return true;
   }
@@ -592,6 +598,27 @@ const AXObject* AXObject::ariaHiddenRoot() const {
   return 0;
 }
 
+const AXObject* AXObject::inertRoot() const {
+  const AXObject* object = this;
+  if (!RuntimeEnabledFeatures::inertAttributeEnabled())
+    return nullptr;
+
+  while (object && !object->isAXNodeObject())
+    object = object->parentObject();
+  Node* node = object->getNode();
+  node->updateDistribution();

[esprehn, 2017/02/16 06:28:12]

updateDistribution can actually cause a detach(), which can then destroy and
recrete the AXObject tree, I think you want to call this higher up in the
system?

Actually since this is inside the AXObject tree, and that depends on style, this
should only be used after we called updateStyle() which updates distribution, so
can distribution be dirty here?

+  Element* element = node->isElementNode()
+                         ? toElement(node)
+                         : FlatTreeTraversal::parentElement(*node);
+  while (element) {
+    if (element->hasAttribute(inertAttr))
+      return axObjectCache().getOrCreate(element);
+    element = FlatTreeTraversal::parentElement(*element);
+  }
+
+  return nullptr;
+}
+
 bool AXObject::isDescendantOfDisabledNode() const {
   updateCachedAttributeValuesIfNeeded();
   return m_cachedIsDescendantOfDisabledNode;