Move MediaQuery classes off BlinkGC heap

third_party/WebKit/Source/core/css/StyleRule.cpp

Index: third_party/WebKit/Source/core/css/StyleRule.cpp
diff --git a/third_party/WebKit/Source/core/css/StyleRule.cpp b/third_party/WebKit/Source/core/css/StyleRule.cpp
index 2bcbd8c969ef66d0f789397c08c1255c6ea13d43..dbb1da13549ba06dd1f2ff6bb686ea39afa43d37 100644
--- a/third_party/WebKit/Source/core/css/StyleRule.cpp
+++ b/third_party/WebKit/Source/core/css/StyleRule.cpp
@@ -352,7 +352,7 @@ StyleRuleCondition::StyleRuleCondition(const StyleRuleCondition& conditionRule)
     : StyleRuleGroup(conditionRule),
       m_conditionText(conditionRule.m_conditionText) {}
 
-StyleRuleMedia::StyleRuleMedia(MediaQuerySet* media,
+StyleRuleMedia::StyleRuleMedia(RefPtr<MediaQuerySet> media,
                                HeapVector<Member<StyleRuleBase>>& adoptRules)
     : StyleRuleCondition(Media, adoptRules), m_mediaQueries(media) {}
 
@@ -363,7 +363,6 @@ StyleRuleMedia::StyleRuleMedia(const StyleRuleMedia& mediaRule)
 }
 
 DEFINE_TRACE_AFTER_DISPATCH(StyleRuleMedia) {
-  visitor->trace(m_mediaQueries);
   StyleRuleCondition::traceAfterDispatch(visitor);
 }