Make CSSParserContext be garbage collected.

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

Index: third_party/WebKit/Source/core/loader/resource/CSSStyleSheetResource.cpp
diff --git a/third_party/WebKit/Source/core/loader/resource/CSSStyleSheetResource.cpp b/third_party/WebKit/Source/core/loader/resource/CSSStyleSheetResource.cpp
index 41dea66b4356d384e1a6e69a1ae06e87d179a913..d5e893084504e69714e6e356109dc0f5ff630027 100644
--- a/third_party/WebKit/Source/core/loader/resource/CSSStyleSheetResource.cpp
+++ b/third_party/WebKit/Source/core/loader/resource/CSSStyleSheetResource.cpp
@@ -186,7 +186,7 @@ bool CSSStyleSheetResource::canUseSheet(MIMETypeCheck mimeTypeCheck) const {
 }
 
 StyleSheetContents* CSSStyleSheetResource::restoreParsedStyleSheet(
-    const CSSParserContext& context) {
+    const CSSParserContext* context) {
   if (!m_parsedStyleSheetCache)
     return nullptr;
   if (m_parsedStyleSheetCache->hasFailedOrCanceledSubresources()) {
@@ -199,7 +199,7 @@ StyleSheetContents* CSSStyleSheetResource::restoreParsedStyleSheet(
 
   // 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)

[rune, 2017/01/11 12:59:26]

I don't think you need parentheses here. *a->b() is the same as *(a->b()), not
(*a)->b().

[Bret, 2017/01/11 23:05:15]

Done.

     return nullptr;
 
   return m_parsedStyleSheetCache;