Make CSSParserContext be garbage collected.

third_party/WebKit/Source/core/loader/resource/CSSStyleSheetResource.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.
 
     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
@@ skipping 168 matching lines @@
   // This code defaults to allowing the stylesheet for non-HTTP protocols so
   // folks can use standards mode for local HTML documents.
   if (mimeTypeCheck == MIMETypeCheck::Lax)
     return true;
   AtomicString contentType = httpContentType();
   return contentType.isEmpty() || equalIgnoringCase(contentType, "text/css") ||
          equalIgnoringCase(contentType, "application/x-unknown-content-type");
 }
 
 StyleSheetContents* CSSStyleSheetResource::restoreParsedStyleSheet(
-    const CSSParserContext& context) {
+    const CSSParserContext* context) {
   if (!m_parsedStyleSheetCache)
     return nullptr;
   if (m_parsedStyleSheetCache->hasFailedOrCanceledSubresources()) {
     setParsedStyleSheetCache(nullptr);
     return nullptr;
   }
 
   DCHECK(m_parsedStyleSheetCache->isCacheableForResource());
   DCHECK(m_parsedStyleSheetCache->isReferencedFromResource());
 
   // Contexts must be identical so we know we would get the same exact result if
   // we parsed again.
-  if (m_parsedStyleSheetCache->parserContext() != context)
+  if (*m_parsedStyleSheetCache->parserContext() != *context)
     return nullptr;
 
   return m_parsedStyleSheetCache;
 }
 
 void CSSStyleSheetResource::saveParsedStyleSheet(StyleSheetContents* sheet) {
   DCHECK(sheet);
   DCHECK(sheet->isCacheableForResource());
 
   if (!memoryCache()->contains(this)) {
@@ skipping 12 matching lines @@
 }
 
 void CSSStyleSheetResource::updateDecodedSize() {
   size_t decodedSize = m_decodedSheetText.charactersSizeInBytes();
   if (m_parsedStyleSheetCache)
     decodedSize += m_parsedStyleSheetCache->estimatedSizeInBytes();
   setDecodedSize(decodedSize);
 }
 
 }  // namespace blink