Remove some unused code

Source/core/dom/ProcessingInstruction.cpp

Index: Source/core/dom/ProcessingInstruction.cpp
diff --git a/Source/core/dom/ProcessingInstruction.cpp b/Source/core/dom/ProcessingInstruction.cpp
index aca9261fa0f88838620bcc97526cd89b63b73a48..a4cc838d633af219f8fe5414c0f0fcc023ebc0e6 100644
--- a/Source/core/dom/ProcessingInstruction.cpp
+++ b/Source/core/dom/ProcessingInstruction.cpp
@@ -258,15 +258,6 @@ void ProcessingInstruction::parseStyleSheet(const String& sheet)
         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);