Fix null ptr exception

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

Index: third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp
diff --git a/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp b/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp
index 0cd2a4c716ba9463955c5f3155aff949cac081db..4dcff4e86f30d9e3fc92baa76824b91574628b4c 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp
@@ -543,8 +543,9 @@ AccessibilityRole AXNodeObject::NativeAccessibilityRoleIgnoringAria() const {
   if (isHTMLOptionElement(*GetNode())) {
     HTMLSelectElement* select_element =
         toHTMLOptionElement(GetNode())->OwnerSelectElement();
-    return select_element->IsMultiple() ? kListBoxOptionRole
-                                        : kMenuListOptionRole;
+    return !select_element || select_element->IsMultiple()
+               ? kListBoxOptionRole
+               : kMenuListOptionRole;
   }
 
   if (isHTMLTextAreaElement(*GetNode()))