Implement the inert attribute

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

Index: third_party/WebKit/Source/modules/accessibility/AXObject.h
diff --git a/third_party/WebKit/Source/modules/accessibility/AXObject.h b/third_party/WebKit/Source/modules/accessibility/AXObject.h
index a7c59cbc2d9865e161e0c89fa780a57fefba8c28..9fd1ee14b0dfbe4f45913c943d1bd578707b4b80 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXObject.h
+++ b/third_party/WebKit/Source/modules/accessibility/AXObject.h
@@ -399,11 +399,12 @@ enum AXIgnoredReason {
   kAXActiveModalDialog,
   kAXAncestorDisallowsChild,
   kAXAncestorIsLeafNode,
-  kAXAriaHidden,
-  kAXAriaHiddenRoot,
+  kAXAriaHiddenElement,
+  kAXAriaHiddenSubtree,
   kAXEmptyAlt,
   kAXEmptyText,
-  kAXInert,
+  kAXInertElement,
+  kAXInertSubtree,
   kAXInheritsPresentation,
   kAXLabelContainer,
   kAXLabelFor,
@@ -712,7 +713,7 @@ class MODULES_EXPORT AXObject : public GarbageCollectedFinalized<AXObject> {
   virtual bool CanSetSelectedAttribute() const { return false; }
 
   // Whether objects are ignored, i.e. not included in the tree.
-  bool AccessibilityIsIgnored() const;
+  bool AccessibilityIsIgnored();
   typedef HeapVector<IgnoredReason> IgnoredReasons;
   virtual bool ComputeAccessibilityIsIgnored(IgnoredReasons* = nullptr) const {
     return true;
@@ -1097,6 +1098,8 @@ class MODULES_EXPORT AXObject : public GarbageCollectedFinalized<AXObject> {
     return nullptr;
   }
 
+  const AXObject* InertRoot() const;
+
   mutable Member<AXObject> parent_;
 
   // The following cached attribute values (the ones starting with m_cached*)