Introduce createRange(const EphemeralRange&)

Source/web/WebRange.cpp

 /*
  * Copyright (C) 2009 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 62 matching lines @@
 {
     return m_private->text();
 }
 
 // static
 WebRange WebRange::fromDocumentRange(WebLocalFrame* frame, int start, int length)
 {
     LocalFrame* webFrame = toWebLocalFrameImpl(frame)->frame();
     Element* selectionRoot = webFrame->selection().rootEditableElement();
     ContainerNode* scope = selectionRoot ? selectionRoot : webFrame->document()->documentElement();
-    const EphemeralRange range = PlainTextRange(start, start + length).createRange(*scope);
-    if (range.isNull())
-        return WebRange();
-    return Range::create(range.document(), range.startPosition(), range.endPosition());
+    return createRange(PlainTextRange(start, start + length).createRange(*scope));
 }
 
 WebRange::WebRange(const PassRefPtrWillBeRawPtr<Range>& range)
     : m_private(range)
 {
 }
 
 WebRange::operator PassRefPtrWillBeRawPtr<Range>() const
 {
     return m_private.get();
 }
 
 } // namespace blink