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

Source/core/editing/FrameSelection.cpp

Index: Source/core/editing/FrameSelection.cpp
diff --git a/Source/core/editing/FrameSelection.cpp b/Source/core/editing/FrameSelection.cpp
index 2ed84aac4e26e24e5a3b7ebbc8ed1c4142092392..b8da536a4a1c921caf3c24abe5365d20195a512c 100644
--- a/Source/core/editing/FrameSelection.cpp
+++ b/Source/core/editing/FrameSelection.cpp
@@ -1823,8 +1823,7 @@ void FrameSelection::setSelectionFromNone()
     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));
 }