Oilpan: Reapply: Remove all the RefPtrs and most of the raw pointers to style

Source/core/dom/ProcessingInstruction.h

Index: Source/core/dom/ProcessingInstruction.h
diff --git a/Source/core/dom/ProcessingInstruction.h b/Source/core/dom/ProcessingInstruction.h
index 374534f75d8a277f2a87cba2b19fc6284b880757..f8cc63be0339237ae1c82d73cf2240efb67e8d32 100644
--- a/Source/core/dom/ProcessingInstruction.h
+++ b/Source/core/dom/ProcessingInstruction.h
@@ -43,7 +43,7 @@ public:
 
     const String& localHref() const { return m_localHref; }
     StyleSheet* sheet() const { return m_sheet.get(); }
-    void setCSSStyleSheet(PassRefPtr<CSSStyleSheet>);
+    void setCSSStyleSheet(PassRefPtrWillBeRawPtr<CSSStyleSheet>);
 
     bool isCSS() const { return m_isCSS; }
     bool isXSL() const { return m_isXSL; }
@@ -73,7 +73,7 @@ private:
     String m_localHref;
     String m_title;
     String m_media;
-    RefPtr<StyleSheet> m_sheet;
+    RefPtrWillBePersistent<StyleSheet> m_sheet;
     bool m_loading;
     bool m_alternate;
     bool m_createdByParser;