Update the accessibility tree when a modal dialog is opened/closed.

Source/core/accessibility/AXObject.cpp

Index: Source/core/accessibility/AXObject.cpp
diff --git a/Source/core/accessibility/AXObject.cpp b/Source/core/accessibility/AXObject.cpp
index 645d886053c0f331e57822afabb9acd466199c57..e42cdbc5527d35ad30574cec5383660cc5a81bd1 100644
--- a/Source/core/accessibility/AXObject.cpp
+++ b/Source/core/accessibility/AXObject.cpp
@@ -289,14 +289,15 @@ AXObjectInclusion AXObject::defaultObjectInclusion() const
 
 bool AXObject::isInertOrAriaHidden() const
 {
-    if (equalIgnoringCase(getAttribute(aria_hiddenAttr), "true"))
-        return true;
-    if (node() && node()->isInert())
-        return true;
-
-    for (AXObject* object = parentObject(); object; object = object->parentObject()) {
+    bool canBeInInertSubtree = true;

[dmazzoni, 2013/11/07 16:35:59]

Do you mean "is allowed to be in inert subtreee" or "might possibly be in inert
subtree"?

If the latter, how about mightBeInInsertSubtree?

[falken, 2013/11/08 05:08:35]

Done.

+    for (const AXObject* object = this; object; object = object->parentObject()) {
         if (equalIgnoringCase(object->getAttribute(aria_hiddenAttr), "true"))
             return true;
+        if (canBeInInertSubtree && object->node()) {
+            if (object->node()->isInert())
+                return true;
+            canBeInInertSubtree = false;
+        }
     }
 
     return false;
@@ -816,13 +817,15 @@ void AXObject::scrollToGlobalPoint(const IntPoint& globalPoint) const
     }
 }
 
-void AXObject::notifyIfIgnoredValueChanged()
+bool AXObject::notifyIfIgnoredValueChanged()
 {
     bool isIgnored = accessibilityIsIgnored();
     if (lastKnownIsIgnoredValue() != isIgnored) {
         axObjectCache()->childrenChanged(parentObject());
         setLastKnownIsIgnoredValue(isIgnored);
+        return true;
     }
+    return false;
 }
 
 void AXObject::selectionChanged()