Remove some unused code

Source/core/dom/ProcessingInstruction.cpp

 /*
  * Copyright (C) 2000 Peter Kelly (pmk@post.com)
  * Copyright (C) 2006, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 240 matching lines @@
 
     clearResource();
     m_loading = false;
 
     if (m_isCSS)
         toCSSStyleSheet(m_sheet.get())->contents()->checkLoaded();
     else if (m_isXSL)
         toXSLStyleSheet(m_sheet.get())->checkLoaded();
 }
 
-void ProcessingInstruction::setCSSStyleSheet(PassRefPtrWillBeRawPtr<CSSStyleSheet> sheet)
-{
-    ASSERT(!resource());
-    ASSERT(!m_loading);
-    m_sheet = sheet;
-    sheet->setTitle(m_title);
-    sheet->setDisabled(m_alternate);
-}
-
 Node::InsertionNotificationRequest ProcessingInstruction::insertedInto(ContainerNode* insertionPoint)
 {
     CharacterData::insertedInto(insertionPoint);
     if (!insertionPoint->inDocument())
         return InsertionDone;
 
     String href;
     String charset;
     bool isValid = checkStyleSheet(href, charset);
     if (!DocumentXSLT::processingInstructionInsertedIntoDocument(document(), this))
@@ skipping 35 matching lines @@
     m_sheet.release()->clearOwnerNode();
 }
 
 DEFINE_TRACE(ProcessingInstruction)
 {
     visitor->trace(m_sheet);
     CharacterData::trace(visitor);
 }
 
 } // namespace