Translate viewport related meta tags into @viewport descriptors as suggested by the CSS Device Adap…

Source/core/css/resolver/ViewportStyleResolver.h

Index: Source/core/css/resolver/ViewportStyleResolver.h
diff --git a/Source/core/css/resolver/ViewportStyleResolver.h b/Source/core/css/resolver/ViewportStyleResolver.h
index 9f86309dd29b71b3959ff64999a537913982bddf..c2a39c1fa479ebaa9ea8e4cae94e789b2831bf4e 100644
--- a/Source/core/css/resolver/ViewportStyleResolver.h
+++ b/Source/core/css/resolver/ViewportStyleResolver.h
@@ -49,6 +49,8 @@ public:
 
     ~ViewportStyleResolver();
 
+    bool shouldDisableDesktopWorkarounds() const;
+
     void addViewportRule(StyleRuleViewport*);
 
     void clearDocument();
@@ -60,6 +62,7 @@ private:
     float getViewportArgumentValue(CSSPropertyID) const;
 
     Document* m_document;
+    float m_maxPriority;
     RefPtr<MutableStylePropertySet> m_propertySet;
 };