Recompute percentage based @viewport on resize.

Source/core/dom/ViewportArguments.h

Index: Source/core/dom/ViewportArguments.h
diff --git a/Source/core/dom/ViewportArguments.h b/Source/core/dom/ViewportArguments.h
index ea9a44e60a3897fc7dea694aa2383cfdc953ff9b..9eaf555e5f11781fda7cdec86be75e18f6bb4642 100644
--- a/Source/core/dom/ViewportArguments.h
+++ b/Source/core/dom/ViewportArguments.h
@@ -29,6 +29,7 @@
 #define ViewportArguments_h
 
 #include "core/page/PageScaleConstraints.h"
+#include "core/platform/Length.h"
 #include "core/platform/graphics/FloatSize.h"
 #include "wtf/Forward.h"
 
@@ -74,11 +75,7 @@ struct ViewportArguments {
     ViewportArguments(Type type = Implicit)
         : type(type)
         , width(ValueAuto)
-        , minWidth(ValueAuto)
-        , maxWidth(ValueAuto)
         , height(ValueAuto)
-        , minHeight(ValueAuto)
-        , maxHeight(ValueAuto)
         , zoom(ValueAuto)
         , minZoom(ValueAuto)
         , maxZoom(ValueAuto)
@@ -92,11 +89,11 @@ struct ViewportArguments {
     PageScaleConstraints resolve(const FloatSize& initialViewportSize, int defaultWidth) const;
 
     float width;
-    float minWidth;
-    float maxWidth;
+    Length minWidth;
+    Length maxWidth;
     float height;
-    float minHeight;
-    float maxHeight;
+    Length minHeight;
+    Length maxHeight;
     float zoom;
     float minZoom;
     float maxZoom;
@@ -126,6 +123,10 @@ struct ViewportArguments {
     {
         return !(*this == other);
     }
+
+private:
+    enum Direction { Horizontal, Vertical };
+    static float resolveViewportLength(const Length&, const FloatSize& initialViewportSize, Direction);
 };
 
 void setViewportFeature(const String& keyString, const String& valueString, Document*, void* data);