Support the essential part of Shadow DOM v1

third_party/WebKit/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 601 matching lines @@
 Node* Internals::previousInComposedTree(Node* node, ExceptionState& exceptionState)
 {
     ASSERT(node);
     if (!node->canParticipateInComposedTree()) {
         exceptionState.throwDOMException(InvalidAccessError, "The node argument doesn't particite in the composed tree.");
         return 0;
     }
     return ComposedTreeTraversal::previous(*node);
 }
 
+Node* Internals::parentInComposedTree(Node* node, ExceptionState& exceptionState)
+{
+    ASSERT(node);
+    if (!node->canParticipateInComposedTree()) {
+        exceptionState.throwDOMException(InvalidAccessError, "The node argument doesn't particite in the composed tree.");
+        return nullptr;

[kochi, 2015/12/09 08:57:34]

nit: could you convert all other instances of "return 0;" in this file to
"return nullptr" in another CL?

[hayato, 2015/12/09 10:25:40]

Acknowledged. That can be done later.

+    }
+    return ComposedTreeTraversal::parent(*node);
+}
+
 String Internals::elementLayoutTreeAsText(Element* element, ExceptionState& exceptionState)
 {
     ASSERT(element);
     String representation = externalRepresentation(element);
     if (representation.isEmpty()) {
         exceptionState.throwDOMException(InvalidAccessError, "The element provided has no external representation.");
         return String();
     }
 
     return representation;
@@ skipping 1916 matching lines @@
     mediaElement->setNetworkState(static_cast<WebMediaPlayer::NetworkState>(state));
 }
 
 // TODO(liberato): remove once autoplay gesture override experiment concludes.
 void Internals::triggerAutoplayViewportCheck(HTMLMediaElement* element)
 {
     element->triggerAutoplayViewportCheckForTesting();
 }
 
 } // namespace blink