Robustify window.internals.textSurroundingNode().

Source/core/testing/Internals.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 2296 matching lines @@
     ContextLifecycleObserver::trace(visitor);
 }
 
 void Internals::setValueForUser(Element* element, const String& value)
 {
     toHTMLInputElement(element)->setValueForUser(value);
 }
 
 String Internals::textSurroundingNode(Node* node, int x, int y, unsigned long maxLength)
 {
-    if (!node)
+    if (!node || !node->layoutObject())
         return String();
     blink::WebPoint point(x, y);
     SurroundingText surroundingText(VisiblePosition(node->layoutObject()->positionForPoint(static_cast<IntPoint>(point))).deepEquivalent().parentAnchoredEquivalent(), maxLength);
     return surroundingText.content();
 }
 
 void Internals::setFocused(bool focused)
 {
     frame()->page()->focusController().setFocused(focused);
 }
@@ skipping 128 matching lines @@
     return ClientRectList::create(rects);
 }
 
 void Internals::setCapsLockState(bool enabled)
 {
     PlatformKeyboardEvent::setCurrentCapsLockState(enabled ?
         PlatformKeyboardEvent::OverrideCapsLockState::On : PlatformKeyboardEvent::OverrideCapsLockState::Off);
 }
 
 } // namespace blink