AX:Null pointer may be dereferenced in AXObjectCache.cpp

Source/core/accessibility/AXObjectCache.cpp

Index: Source/core/accessibility/AXObjectCache.cpp
diff --git a/Source/core/accessibility/AXObjectCache.cpp b/Source/core/accessibility/AXObjectCache.cpp
index 34d6f630f5cd16646d3f59affaeff7380b60aafb..2590d5e48f3c02da1e1617b1afad687900d46c5f 100644
--- a/Source/core/accessibility/AXObjectCache.cpp
+++ b/Source/core/accessibility/AXObjectCache.cpp
@@ -343,6 +343,11 @@ AXObject* AXObjectCache::getOrCreate(Widget* widget)
     // Will crash later if we have two objects for the same widget.
     ASSERT(!get(widget));
 
+    // Catch the case if an (unsupported) widget type is used. Only FrameView and ScrollBar are supported now.
+    ASSERT(newObj);
+    if (!newObj)
+        return 0;
+
     getAXID(newObj.get());
 
     m_widgetObjectMapping.set(widget, newObj->axObjectID());