Accessibility events should be sent to the axObjectCacheOwner's frame.

Source/web/ChromeClientImpl.cpp

Index: Source/web/ChromeClientImpl.cpp
diff --git a/Source/web/ChromeClientImpl.cpp b/Source/web/ChromeClientImpl.cpp
index ee5bdbe1b2693ecb9f3d38f744f804418b04287b..e4caefd46ea36d54a5062e16710b2c7679c9a977 100644
--- a/Source/web/ChromeClientImpl.cpp
+++ b/Source/web/ChromeClientImpl.cpp
@@ -665,10 +665,10 @@ void ChromeClientImpl::setCursorForPlugin(const WebCursorInfo& cursor)
 void ChromeClientImpl::postAccessibilityNotification(AXObject* obj, AXObjectCache::AXNotification notification)
 {
     // Alert assistive technology about the accessibility object notification.
-    if (!obj || !obj->documentFrameView())
+    if (!obj || !obj->document())
         return;
 
-    WebLocalFrameImpl* webframe = WebLocalFrameImpl::fromFrame(obj->documentFrameView()->frame());
+    WebLocalFrameImpl* webframe = WebLocalFrameImpl::fromFrame(obj->document()->axObjectCacheOwner().frame());
     if (webframe && webframe->client())
         webframe->client()->postAccessibilityEvent(WebAXObject(obj), toWebAXEvent(notification));