The node and allowPartialContainment arguments for Selection API should not be optional

Source/core/editing/DOMSelection.cpp

 /*
  * Copyright (C) 2007, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2012 Google 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 438 matching lines @@
     if (!selectedRange)
         return;
 
     selectedRange->deleteContents(ASSERT_NO_EXCEPTION);
 
     setBaseAndExtent(selectedRange->startContainer(), selectedRange->startOffset(), selectedRange->startContainer(), selectedRange->startOffset(), ASSERT_NO_EXCEPTION);
 }
 
 bool DOMSelection::containsNode(const Node* n, bool allowPartial) const
 {
+    ASSERT(n);
+
     if (!m_frame)
         return false;
 
     FrameSelection& selection = m_frame->selection();
 
-    if (!n || m_frame->document() != n->document() || selection.isNone())
+    if (m_frame->document() != n->document() || selection.isNone())
         return false;
 
     unsigned nodeIndex = n->nodeIndex();
     const EphemeralRange selectedRange = selection.selection().toNormalizedEphemeralRange();
 
     ContainerNode* parentNode = n->parentNode();
     if (!parentNode)
         return false;
 
     const Position startPosition = selectedRange.startPosition().toOffsetInAnchor();
@@ skipping 81 matching lines @@
         m_treeScope->document().addConsoleMessage(ConsoleMessage::create(JSMessageSource, ErrorMessageLevel, message));
 }
 
 DEFINE_TRACE(DOMSelection)
 {
     visitor->trace(m_treeScope);
     DOMWindowProperty::trace(visitor);
 }
 
 } // namespace blink