Move MediaQuery classes off BlinkGC heap

third_party/WebKit/Source/core/css/CSSStyleSheet.h

Index: third_party/WebKit/Source/core/css/CSSStyleSheet.h
diff --git a/third_party/WebKit/Source/core/css/CSSStyleSheet.h b/third_party/WebKit/Source/core/css/CSSStyleSheet.h
index b8102a42cb142300235aaf259ed830b70227a5af..2eaa9258d6d04f55219f9eafc9b75669f3b62755 100644
--- a/third_party/WebKit/Source/core/css/CSSStyleSheet.h
+++ b/third_party/WebKit/Source/core/css/CSSStyleSheet.h
@@ -100,8 +100,8 @@ class CORE_EXPORT CSSStyleSheet final : public StyleSheet {
 
   void clearOwnerRule() { m_ownerRule = nullptr; }
   Document* ownerDocument() const;
-  const MediaQuerySet* mediaQueries() const { return m_mediaQueries; }
-  void setMediaQueries(MediaQuerySet*);
+  const MediaQuerySet* mediaQueries() const { return m_mediaQueries.get(); }
+  void setMediaQueries(RefPtr<MediaQuerySet>);
   bool matchesMediaQueries(const MediaQueryEvaluator&);
   const MediaQueryResultList& viewportDependentMediaQueryResults() const {
     return m_viewportDependentMediaQueryResults;
@@ -164,7 +164,7 @@ class CORE_EXPORT CSSStyleSheet final : public StyleSheet {
   bool m_isDisabled = false;
   bool m_loadCompleted = false;
   String m_title;
-  Member<MediaQuerySet> m_mediaQueries;
+  RefPtr<MediaQuerySet> m_mediaQueries;
   MediaQueryResultList m_viewportDependentMediaQueryResults;
   MediaQueryResultList m_deviceDependentMediaQueryResults;