Separate @viewport from other RuleSet construction.

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 6af05ee6565b0a6b5402575d976850f362c8116c..d07be56852a1055ea3f8a47d413b0f2668219efb 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"
 
@@ -48,25 +49,33 @@ class CORE_EXPORT ViewportStyleResolver
     return new ViewportStyleResolver(document);
   }
 
-  enum Origin { UserAgentOrigin, AuthorOrigin };
-
-  void collectViewportRules();
-  void collectViewportRules(RuleSet*, Origin);
+  void reset();
+  void collectViewportRulesFromUASheets();
+  void collectViewportRulesFromAuthorSheet(const CSSStyleSheet&);
   void resolve();
+  bool isAffectedByInitialViewportChange();
 
   DECLARE_TRACE();
 
  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;
+  Length viewportLengthValue(CSSPropertyID);
 
   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;
+  bool m_hasViewportUnits = false;
 };
 
 }  // namespace blink