Simplify code for finding body in FrameSelection::setSelectionFromNone()

Source/core/editing/FrameSelection.cpp

 /*
  * Copyright (C) 2004, 2008, 2009, 2010 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1805 matching lines @@
     // entire WebView is editable or designMode is on for this document).
 
     Document* document = m_frame->document();
     bool caretBrowsing = m_frame->settings() && m_frame->settings()->caretBrowsingEnabled();
     if (!isNone() || !(document->hasEditableStyle() || caretBrowsing))
         return;
 
     Element* documentElement = document->documentElement();
     if (!documentElement)
         return;
-    HTMLBodyElement* body = isHTMLBodyElement(*documentElement) ? toHTMLBodyElement(documentElement) : Traversal<HTMLBodyElement>::next(*documentElement);
-    if (body)
+    if (HTMLBodyElement* body = Traversal<HTMLBodyElement>::firstChild(*documentElement))
         setSelection(VisibleSelection(firstPositionInOrBeforeNode(body), DOWNSTREAM));
 }
 
 bool FrameSelection::dispatchSelectStart()
 {
     Node* selectStartTarget = m_selection.extent().containerNode();
     if (!selectStartTarget)
         return true;
 
     return selectStartTarget->dispatchEvent(Event::createCancelableBubble(EventTypeNames::selectstart));
@@ skipping 87 matching lines @@
     sel.showTreeForThis();
 }
 
 void showTree(const blink::FrameSelection* sel)
 {
     if (sel)
         sel->showTreeForThis();
 }
 
 #endif