Have srcset respond to viewport changes

Source/core/css/parser/SizesCalcParser.h

Index: Source/core/css/parser/SizesCalcParser.h
diff --git a/Source/core/css/parser/SizesCalcParser.h b/Source/core/css/parser/SizesCalcParser.h
index 5d18b30176e8572e439f1440215e2a889060af72..3611219c9200e410426ccb27b3fdb5de1b1a825c 100644
--- a/Source/core/css/parser/SizesCalcParser.h
+++ b/Source/core/css/parser/SizesCalcParser.h
@@ -34,16 +34,15 @@ struct SizesCalcValue {
 class SizesCalcParser {
 
 public:
-    static bool parse(MediaQueryTokenIterator start, MediaQueryTokenIterator end, PassRefPtr<MediaValues>, unsigned& result);
+    SizesCalcParser(MediaQueryTokenIterator start, MediaQueryTokenIterator end, PassRefPtr<MediaValues>);
 
-private:
-    SizesCalcParser(PassRefPtr<MediaValues> mediaValues)
-        : m_mediaValues(mediaValues)
-    {
-    }
+    bool viewportDependant() const { return m_viewportDependant; }
+    unsigned result() const;
+    bool isValid() const { return m_isValid; }
 
+private:
     bool calcToReversePolishNotation(MediaQueryTokenIterator start, MediaQueryTokenIterator end);
-    bool calculate(unsigned& result);
+    bool calculate();
     void appendNumber(const MediaQueryToken&);
     bool appendLength(const MediaQueryToken&);
     bool handleOperator(Vector<MediaQueryToken>& stack, const MediaQueryToken&);
@@ -51,6 +50,9 @@ private:
 
     Vector<SizesCalcValue> m_valueList;
     RefPtr<MediaValues> m_mediaValues;
+    bool m_viewportDependant;
+    bool m_isValid;
+    unsigned m_result;
 };
 
 } // namespace blink