Use css-device-adapt constraining for legacy viewport tags.

Source/core/css/resolver/StyleResolver.h

Index: Source/core/css/resolver/StyleResolver.h
diff --git a/Source/core/css/resolver/StyleResolver.h b/Source/core/css/resolver/StyleResolver.h
index 7e96b72cefc67bdd2180dbb9bfda6779638babb4..2a78cb7be7c4babb3ee4a4d7ecd6fcce08b3ac16 100644
--- a/Source/core/css/resolver/StyleResolver.h
+++ b/Source/core/css/resolver/StyleResolver.h
@@ -265,9 +265,11 @@ public:
     // FIXME: StyleResolver should not have this member or method.
     InspectorCSSOMWrappers& inspectorCSSOMWrappers() { return m_inspectorCSSOMWrappers; }
 
+    enum ViewportOrigin { UserAgentOrigin, AuthorOrigin };
+
     // Exposed for ScopedStyleResolver.
     // FIXME: Likely belongs on viewportStyleResolver.
-    void collectViewportRules(RuleSet*);
+    void collectViewportRules(RuleSet*, ViewportOrigin);
 
     const RuleFeatureSet& ruleFeatureSet() const { return m_features; }