Current work-in-progress crbug.com/567021

third_party/WebKit/Source/core/css/resolver/ViewportStyleResolver.h

Index: third_party/WebKit/Source/core/css/resolver/ViewportStyleResolver.h
diff --git a/third_party/WebKit/Source/core/css/resolver/ViewportStyleResolver.h b/third_party/WebKit/Source/core/css/resolver/ViewportStyleResolver.h
index f91cdba7043f3b9d9ad0ee97ec20042b716c651c..847ed9de852bcca35a56a0110b023378f028540b 100644
--- a/third_party/WebKit/Source/core/css/resolver/ViewportStyleResolver.h
+++ b/third_party/WebKit/Source/core/css/resolver/ViewportStyleResolver.h
@@ -32,6 +32,7 @@
 
 #include "core/CSSPropertyNames.h"
 #include "core/CoreExport.h"
+#include "core/css/MediaQueryEvaluator.h"
 #include "core/css/RuleSet.h"
 #include "platform/Length.h"
 
@@ -48,10 +49,9 @@ public:
         return new ViewportStyleResolver(document);
     }
 
-    enum Origin { UserAgentOrigin, AuthorOrigin };
-
-    void collectViewportRules();
-    void collectViewportRules(RuleSet*, Origin);
+    void reset();
+    void collectViewportRulesFromUASheets();
+    void collectViewportRulesFromAuthorSheet(const CSSStyleSheet&);
     void resolve();
 
     DECLARE_TRACE();
@@ -59,14 +59,20 @@ public:
 private:
     explicit ViewportStyleResolver(Document*);
 
-    void addViewportRule(StyleRuleViewport*, Origin);
+    enum Origin { UserAgentOrigin, AuthorOrigin };
+
+    void collectViewportChildRules(const HeapVector<Member<StyleRuleBase>>&, Origin);
+    void addViewportRule(StyleRuleViewport&, Origin);
 
     float viewportArgumentValue(CSSPropertyID) const;
     Length viewportLengthValue(CSSPropertyID) const;
 
     Member<Document> m_document;
     Member<MutableStylePropertySet> m_propertySet;
-    bool m_hasAuthorStyle;
+    Member<MediaQueryEvaluator> m_initialViewportMedium;
+    MediaQueryResultList m_viewportDependentMediaQueryResults;
+    MediaQueryResultList m_deviceDependentMediaQueryResults;
+    bool m_hasAuthorStyle = false;
 };
 
 } // namespace blink